Excitation spectrum of ferromagnetic xxz-chains
International Nuclear Information System (INIS)
Schneider, T.; Stoll, E.
1983-01-01
In the history of xxz-Heisenberg spin chains, understanding of the dynamic form factors (DFF) is much less advanced. In this paper the DFF of ferromagnetic xxz chains as a tool to probe and interpret excitation spectrum is reviewed. The Isingheisenberg chain, and the Planar-Heisenberg chain (where HF approximations become exact) are studied. The results provide instructive connections between spin systems, interacting fermions and bosons. Various new aspects--thermally induced bound state effects in terms of central peaks in DFF for Isinglike xxz chains; the possibility to observe bound states in S /SUB zz/ (q,w) accessible by neutron scattering techniques, in the planar system--are found
Energy Technology Data Exchange (ETDEWEB)
Wu, Wei [Zhejiang Institute of Modern Physics and Department of Physics, Zhejiang University, Hangzhou 310027 (China); Beijing Computational Science Research Center, Beijing 100193 (China); Xu, Jing-Bo, E-mail: xujb@zju.edu.cn [Zhejiang Institute of Modern Physics and Department of Physics, Zhejiang University, Hangzhou 310027 (China)
2017-01-30
We investigate the performances of quantum coherence and multipartite entanglement close to the quantum critical point of a one-dimensional anisotropic spin-1/2 XXZ spin chain by employing the real-space quantum renormalization group approach. It is shown that the quantum criticality of XXZ spin chain can be revealed by the singular behaviors of the first derivatives of renormalized quantum coherence and multipartite entanglement in the thermodynamics limit. Moreover, we find the renormalized quantum coherence and multipartite entanglement obey certain universal exponential-type scaling laws in the vicinity of the quantum critical point of XXZ spin chain. - Highlights: • The QPT of XXZ chain is studied by renormalization group. • The renormalized coherence and multiparticle entanglement is investigated. • Scaling laws of renormalized coherence and multiparticle entanglement are revealed.
Teleportation via thermally entangled states of a two-qubit Heisenberg XXZ chain
Institute of Scientific and Technical Information of China (English)
QIN Meng; TAO Ying-Juan; TIAN Dong-Ping
2008-01-01
We investigate quantum teleportation as a tool to study the thermally entangled state of a twoqubit Heisenberg XXZ chain.Our work is mainly to investigate the characteristics of a Heisenberg XXZ chain and get some analytical results of the fully entangled fraction.We also consider the entanglement teleportation via a two-qubit Heisenberg XXZ chain.
On the particle excitations in the XXZ spin chain
Energy Technology Data Exchange (ETDEWEB)
Ovchinnikov, A.A., E-mail: ovch@ms2.inr.ac.ru
2013-12-09
We continue to study the excited states for the XXZ spin chain corresponding to the complex roots of the Bethe Ansatz equations with the imaginary part equal to π/2. We propose the particle–hole symmetry which relates the eigenstates build up from the two different pseudovacuum states. We find the XXX spin chain limit for the eigenstates with the complex roots. We also comment on the low-energy excited states for the XXZ spin chain.
On integrable Hamiltonians for higher spin XXZ chain
International Nuclear Information System (INIS)
Bytsko, Andrei G.
2003-01-01
Integrable Hamiltonians for higher spin periodic XXZ chains are constructed in terms of the spin generators; explicit examples for spins up to (3/2) are given. Relations between Hamiltonians for some U q (sl 2 )-symmetric and U(1)-symmetric universal r-matrices are studied; their properties are investigated. A certain modification of the higher spin periodic chain Hamiltonian is shown to be an integrable U q (sl 2 )-symmetric Hamiltonian for an open chain
Connections of the Liouville model and XXZ spin chain
Faddeev, Ludvig D.; Tirkkonen, Olav
1995-02-01
The quantum theory of the Liouville model with imaginary field is considered using the Quantum Inverse Scattering Method. An integrable structure with non-trivial spectral-parameter dependence is developed for lattice Liouville theory by scaling the L-matrix of lattice sine-Gordon theory. This L-matrix yields Bethe ansatz equations for Liouville theory, by the methods of the algebraic Bethe ansatz. Using the string picture of excited Bethe states, the lattice Liouville Bethe equations are mapped to the corresponding spin- {1}/{2} XXZ chain equations. The well developed theory of finite-size corrections in spin chains is used to deduce the conformal properties of the lattice Liouville Bethe states. The unitary series of conformal field theories emerge for Liouville couplings of the form γ = πν/( ν + 1), corresponding to root of unity XXZ anisotropies. The Bethe states give the full spectrum of the corresponding unitary conformal field theory, with the primary states in the Kač table parameterized by a string length K, and the remnant of the chain length mod ( ν + 1).
Connections of the Liouville model and XXZ spin chain
International Nuclear Information System (INIS)
Faddeev, L.D.; Tirkkonen, O.
1995-01-01
The quantum theory of the Liouville model with imaginary field is considered using the Quantum Inverse Scattering Method. An integrable structure with non-trivial spectral-parameter dependence is developed for lattice Liouville theory by scaling the L-matrix of lattice sine-Gordon theory. This L-matrix yields Bethe ansatz equations for Liouville theory, by the methods of the algebraic Bethe ansatz. Using the string picture of excited Bethe states, the lattice Liouville Bethe equations are mapped to the corresponding spin-1/2 XXZ chain equations. The well developed theory of finite-size corrections in spin chains is used to deduce the conformal properties of the lattice Liouville Bethe states. The unitary series of conformal field theories emerge for Liouville couplings of the form γ= πν/(ν+1), corresponding to root of unity XXZ anisotropies. The Bethe states give the full spectrum of the corresponding unitary conformal field theory, with the primary states in the Kac table parameterized by a string length K, and the remnant of the chain length mod (ν+1). (orig.)
Global entanglement in XXZ chains
International Nuclear Information System (INIS)
Canosa, N.; Rossignoli, R.
2006-01-01
We examine the thermal entanglement of XXZ-type Heisenberg chains in the presence of a uniform magnetic field along the z axes through the evaluation of the negativity associated with bipartitions of the whole system and subsystems. Limit temperatures for nonzero global negativities are shown to depend on the asymmetry Δ, but not on the uniform field, and can be much higher than those limiting pairwise entanglement. It is also shown that global bipartite entanglement may exist for T>0 even for Δ≥1, i.e., when the system is fully aligned (and hence separable) at T=0, and that the bipartition leading to the highest limit temperature depends on Δ
Generic boundary scattering in the open XXZ chain
International Nuclear Information System (INIS)
Doikou, Anastasia
2008-01-01
The open critical XXZ spin chain with a general right boundary and a trivial diagonal left boundary is considered. Within this framework we propose a simple computation of the exact generic boundary S-matrix (with diagonal and non-diagonal entries), starting from the 'bare' Bethe ansatz equations. Our results as anticipated coincide with the ones obtained by Ghoshal and Zamolodchikov, after assuming suitable identifications of the bulk and boundary parameters
International Nuclear Information System (INIS)
Guo Ketao; Liang Mingchao; Xu Hongyu; Zhu Chengbo
2010-01-01
Using the concept of negativity, we investigate the thermal entanglement of a two-spin (1/2, 3/2) mixed-spin Heisenberg XXZ chain with an inhomogeneous external magnetic field. We obtain the analytical results of entanglement of this model. For the case of uniform magnetic field, we find that the critical temperature increases with the increase of the anisotropy parameter k, and for the same couplings, the critical temperature is higher than the results of the spin-1/2 XXZ chain and (1/2, 1) mixed-spin XXZ chain. Evidence of the quantum phase transition is found, and by adjusting the inhomogeneous magnetic parameter b, one is able to obtain more entanglement at higher temperature.
The finite temperature density matrix and two-point correlations in the antiferromagnetic XXZ chain
Göhmann, Frank; Hasenclever, Nils P.; Seel, Alexander
2005-10-01
We derive finite temperature versions of integral formulae for the two-point correlation functions in the antiferromagnetic XXZ chain. The derivation is based on the summation of density matrix elements characterizing a finite chain segment of length m. On this occasion we also supply a proof of the basic integral formula for the density matrix presented in an earlier publication.
Finite-temperature behavior of an impurity in the spin-1/2 XXZ chain
International Nuclear Information System (INIS)
Yahagi, Ryoko; Deguchi, Tetsuo; Sato, Jun
2014-01-01
We study the zero- and the finite-temperature behavior of the integrable spin-1/2 XXZ periodic chain with an impurity by the algebraic and thermal Bethe ansatz methods. We evaluate the local magnetization on the impurity site at zero temperature analytically and derive the impurity susceptibility exactly from it. In the graphs of the impurity specific heat versus temperature, we show how the impurity spin becomes more liberated from the bulk many-body effect as the exchange coupling between the impurity spin and other spins decreases and that at low temperature it couples strongly to them such as in the Kondo effect. Thus, we observe not only the crossover behavior from the high- to the low-temperature regime, but another from the N-site chain to the (N − 1)-site chain with a free impurity spin. We also show that the estimate of the Wilson ratio at a given low temperature is independent of the impurity parameter if its absolute value is small enough with respect to the temperature and the universality class is described by the XXZ anisotropy in terms of the dressed charge. (paper)
On domain wall boundary conditions for the XXZ spin Hamiltonian
DEFF Research Database (Denmark)
Orlando, Domenico; Reffert, Susanne; Reshetikhin, Nicolai
In this note, we derive the spectrum of the infinite quantum XXZ spin chain with domain wall boundary conditions. The eigenstates are constructed as limits of Bethe states for the finite XXZ spin chain with quantum sl(2) invariant boundary conditions....
On the semi-classical limit of scalar products of the XXZ spin chain
Energy Technology Data Exchange (ETDEWEB)
Jiang, Yunfeng; Brunekreef, Joren [Institut für Theoretische Physik, ETH Zürich,Wolfgang Pauli Strasse 27, CH-8093 Zürich (Switzerland)
2017-03-03
We study the scalar products between Bethe states in the XXZ spin chain with anisotropy |Δ|>1 in the semi-classical limit where the length of the spin chain and the number of magnons tend to infinity with their ratio kept finite and fixed. Our method is a natural yet non-trivial generalization of similar methods developed for the XXX spin chain. The final result can be written in a compact form as a contour integral in terms of Faddeev’s quantum dilogarithm function, which in the isotropic limit reduces to the classical dilogarithm function.
On the semi-classical limit of scalar products of the XXZ spin chain
International Nuclear Information System (INIS)
Jiang, Yunfeng; Brunekreef, Joren
2017-01-01
We study the scalar products between Bethe states in the XXZ spin chain with anisotropy |Δ|>1 in the semi-classical limit where the length of the spin chain and the number of magnons tend to infinity with their ratio kept finite and fixed. Our method is a natural yet non-trivial generalization of similar methods developed for the XXX spin chain. The final result can be written in a compact form as a contour integral in terms of Faddeev’s quantum dilogarithm function, which in the isotropic limit reduces to the classical dilogarithm function.
Choi, Hwan Bin; Lee, Ji-Woo
2017-09-01
We study quantum phase transitions of a XXZ spin model with spin S = 1/2 and 1 in one dimension. The XXZ spin chain is one of basic models in understanding various one-dimensional magnetic materials. To study this model, we construct infinite-lattice matrix product state (iMPS), which is a tensor product form for a one-dimensional many-body quantum wave function. By using timeevolution- block-decimation method (TEBD) on iMPS, we obtain the ground states of the XXZ model at zero temperature. This method is very delicate in calculating ground states so that we developed a reliable method of finding the ground state with the dimension of entanglement coefficients up to 300, which is beyond the previous works. By analyzing ground-state energies, half-chain entanglement entropies, and entanglement spectrum, we found the signatures of quantum phase transitions between ferromagnetic phase, XY phase, Haldane phase, and antiferromagnetic phase.
Finite-temperature dynamic structure factor of the spin-1 XXZ chain with single-ion anisotropy
Lange, Florian; Ejima, Satoshi; Fehske, Holger
2018-02-01
Improving matrix-product state techniques based on the purification of the density matrix, we are able to accurately calculate the finite-temperature dynamic response of the infinite spin-1 XXZ chain with single-ion anisotropy in the Haldane, large-D , and antiferromagnetic phases. Distinct thermally activated scattering processes make a significant contribution to the spectral weight in all cases. In the Haldane phase, intraband magnon scattering is prominent, and the on-site anisotropy causes the magnon to split into singlet and doublet branches. In the large-D phase response, the intraband signal is separated from an exciton-antiexciton continuum. In the antiferromagnetic phase, holons are the lowest-lying excitations, with a gap that closes at the transition to the Haldane state. At finite temperatures, scattering between domain-wall excitations becomes especially important and strongly enhances the spectral weight for momentum transfer π .
Low-temperature transport in out-of-equilibrium XXZ chains
Bertini, Bruno; Piroli, Lorenzo
2018-03-01
We study the low-temperature transport properties of out-of-equilibrium XXZ spin-1/2 chains. We consider the protocol where two semi-infinite chains are prepared in two thermal states at small but different temperatures and suddenly joined together. We focus on the qualitative and quantitative features of the profiles of local observables, which at large times t and distances x from the junction become functions of the ratio \\zeta=x/t . By means of the generalized hydrodynamic equations, we analyse the rich phenomenology arising by considering different regimes of the phase diagram. In the gapped phases, variations of the profiles are found to be exponentially small in the temperatures, but described by non-trivial functions of ζ. We provide analytical formulae for the latter, which give accurate results also for small but finite temperatures. In the gapless regime, we show how the three-step conformal predictions for the profiles of energy density and energy current are naturally recovered from the hydrodynamic equations. Moreover, we also recover the recent non-linear Luttinger liquid predictions for low-temperature transport: universal peaks of width \
Solving the open XXZ spin chain with nondiagonal boundary terms at roots of unity
International Nuclear Information System (INIS)
Nepomechie, Rafael I.
2002-01-01
We consider the open XXZ quantum spin chain with nondiagonal boundary terms. For bulk anisotropy value η=((iπ)/(p+1)), p=1,2,..., we propose an exact (p+1)-order functional relation for the transfer matrix, which implies Bethe-ansatz-like equations for the corresponding eigenvalues. The key observation is that the fused spin-((p+1)/(2)) transfer matrix can be expressed in terms of a lower-spin transfer matrix, resulting in the truncation of the fusion hierarchy
International Nuclear Information System (INIS)
Grimm, Uwe; Schuetz, Gunter
1992-09-01
The finite-size spectra of the spin-1/2 XXZ Heisenberg chain with toroidal boundary conditions and an even number of sites provide a projection mechanism yielding the spectra of models with central charge c q [sl(2)] quantum algebra transformations. (author)
Directory of Open Access Journals (Sweden)
Tetsuo Deguchi
2011-06-01
Full Text Available We show some symmetry relations among the correlation functions of the integrable higher-spin XXX and XXZ spin chains, where we explicitly evaluate the multiple integrals representing the one-point functions in the spin-1 case. We review the multiple-integral representations of correlation functions for the integrable higher-spin XXZ chains derived in a region of the massless regime including the anti-ferromagnetic point. Here we make use of the gauge transformations between the symmetric and asymmetric R-matrices, which correspond to the principal and homogeneous gradings, respectively, and we send the inhomogeneous parameters to the set of complete 2s-strings. We also give a numerical support for the analytical expression of the one-point functions in the spin-1 case.
International Nuclear Information System (INIS)
Foda, O.; Wheeler, M.; Zuparic, M.
2009-01-01
Using a Jacobi-Trudi-type identity, we show that the scalar product of a general state and a Bethe eigenstate in a finite-length XXZ spin-1/2 chain is (a restriction of) a KP τ function. This leads to a correspondence between the eigenstates and points on Sato's Grassmannian. Each of these points is a function of the rapidities of the corresponding eigenstate, the inhomogeneity variables of the spin chain and the crossing parameter.
Energy Technology Data Exchange (ETDEWEB)
Foda, O. [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)], E-mail: foda@ms.unimelb.edu.au; Wheeler, M. [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)], E-mail: mwheeler@ms.unimelb.edu.au; Zuparic, M. [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)], E-mail: mzup@ms.unimelb.edu.au
2009-10-21
Using a Jacobi-Trudi-type identity, we show that the scalar product of a general state and a Bethe eigenstate in a finite-length XXZ spin-1/2 chain is (a restriction of) a KP {tau} function. This leads to a correspondence between the eigenstates and points on Sato's Grassmannian. Each of these points is a function of the rapidities of the corresponding eigenstate, the inhomogeneity variables of the spin chain and the crossing parameter.
On Condensation Properties of Bethe Roots Associated with the XXZ Chain
Kozlowski, Karol K.
2018-02-01
I prove that the Bethe roots describing either the ground state or a certain class of "particle-hole" excited states of the XXZ spin-1/2 chain in any sector with magnetisation m \\in [0;1/2] exist, are uniquely defined, and form, in the infinite volume limit, a dense distribution on a subinterval of R. The results hold for any value of the anisotropy {Δ ≥ -1}. In fact, I establish an even stronger result, namely the existence of an all order asymptotic expansion of the counting function associated with such roots. As a corollary, these results allow one to prove the existence and form of the infinite volume limit of various observables attached to the model -the excitation energy, momentum, the zero temperature correlation functions, so as to name a few- that were argued earlier in the literature.
Manojlović, N.; Salom, I.
2017-10-01
The implementation of the algebraic Bethe ansatz for the XXZ Heisenberg spin chain in the case, when both reflection matrices have the upper-triangular form is analyzed. The general form of the Bethe vectors is studied. In the particular form, Bethe vectors admit the recurrent procedure, with an appropriate modification, used previously in the case of the XXX Heisenberg chain. As expected, these Bethe vectors yield the strikingly simple expression for the off-shell action of the transfer matrix of the chain as well as the spectrum of the transfer matrix and the corresponding Bethe equations. As in the XXX case, the so-called quasi-classical limit gives the off-shell action of the generating function of the corresponding trigonometric Gaudin Hamiltonians with boundary terms.
International Nuclear Information System (INIS)
Manojlović, N.; Salom, I.
2017-01-01
The implementation of the algebraic Bethe ansatz for the XXZ Heisenberg spin chain in the case, when both reflection matrices have the upper-triangular form is analyzed. The general form of the Bethe vectors is studied. In the particular form, Bethe vectors admit the recurrent procedure, with an appropriate modification, used previously in the case of the XXX Heisenberg chain. As expected, these Bethe vectors yield the strikingly simple expression for the off-shell action of the transfer matrix of the chain as well as the spectrum of the transfer matrix and the corresponding Bethe equations. As in the XXX case, the so-called quasi-classical limit gives the off-shell action of the generating function of the corresponding trigonometric Gaudin Hamiltonians with boundary terms.
Directory of Open Access Journals (Sweden)
N. Manojlović
2017-10-01
Full Text Available The implementation of the algebraic Bethe ansatz for the XXZ Heisenberg spin chain in the case, when both reflection matrices have the upper-triangular form is analyzed. The general form of the Bethe vectors is studied. In the particular form, Bethe vectors admit the recurrent procedure, with an appropriate modification, used previously in the case of the XXX Heisenberg chain. As expected, these Bethe vectors yield the strikingly simple expression for the off-shell action of the transfer matrix of the chain as well as the spectrum of the transfer matrix and the corresponding Bethe equations. As in the XXX case, the so-called quasi-classical limit gives the off-shell action of the generating function of the corresponding trigonometric Gaudin Hamiltonians with boundary terms.
Bounds on the entanglement entropy of droplet states in the XXZ spin chain
Beaud, V.; Warzel, S.
2018-01-01
We consider a class of one-dimensional quantum spin systems on the finite lattice Λ ⊂Z , related to the XXZ spin chain in its Ising phase. It includes in particular the so-called droplet Hamiltonian. The entanglement entropy of energetically low-lying states over a bipartition Λ = B ∪ Bc is investigated and proven to satisfy a logarithmic bound in terms of min{n, |B|, |Bc|}, where n denotes the maximal number of down spins in the considered state. Upon addition of any (positive) random potential, the bound becomes uniformly constant on average, thereby establishing an area law. The proof is based on spectral methods: a deterministic bound on the local (many-body integrated) density of states is derived from an energetically motivated Combes-Thomas estimate.
Heat transport in the XXZ spin chain: from ballistic to diffusive regimes and dephasing enhancement
International Nuclear Information System (INIS)
Mendoza-Arenas, J J; Al-Assam, S; Clark, S R; Jaksch, D
2013-01-01
In this work we study the heat transport in an XXZ spin-1/2 Heisenberg chain with homogeneous magnetic field, incoherently driven out of equilibrium by reservoirs at the boundaries. We focus on the effect of bulk dephasing (energy-dissipative) processes in different parameter regimes of the system. The non-equilibrium steady state of the chain is obtained by simulating its evolution under the corresponding Lindblad master equation, using the time evolving block decimation method. In the absence of dephasing, the heat transport is ballistic for weak interactions, while being diffusive in the strongly interacting regime, as evidenced by the heat current scaling with the system size. When bulk dephasing takes place in the system, diffusive transport is induced in the weakly interacting regime, with the heat current monotonically decreasing with the dephasing rate. In contrast, in the strongly interacting regime, the heat current can be significantly enhanced by dephasing for systems of small size. (paper)
Algebraic Bethe ansatz for the quantum group invariant open XXZ chain at roots of unity
Directory of Open Access Journals (Sweden)
Azat M. Gainutdinov
2016-08-01
Full Text Available For generic values of q, all the eigenvectors of the transfer matrix of the Uqsl(2-invariant open spin-1/2 XXZ chain with finite length N can be constructed using the algebraic Bethe ansatz (ABA formalism of Sklyanin. However, when q is a root of unity (q=eiπ/p with integer p≥2, the Bethe equations acquire continuous solutions, and the transfer matrix develops Jordan cells. Hence, there appear eigenvectors of two new types: eigenvectors corresponding to continuous solutions (exact complete p-strings, and generalized eigenvectors. We propose general ABA constructions for these two new types of eigenvectors. We present many explicit examples, and we construct complete sets of (generalized eigenvectors for various values of p and N.
A note on the boundary spin s XXZ chain
International Nuclear Information System (INIS)
Doikou, Anastasia
2007-01-01
The open spin s XXZ model with non-diagonal boundaries is considered. Within the algebraic Bethe ansatz framework and in the spirit of earlier works we derive suitable reference states. The derivation of the reference state is the crucial point in this investigation, and it involves the solution of sets of difference equations. For the spin s representation, expressed in terms of difference operators, the pseudo-vacuum is identified in terms of q-hypergeometric series. Having specified such states we then build the Bethe states and also identify the spectrum of the model for generic values of the anisotropy parameter q
Monthus, Cécile
2018-03-01
For the line of critical antiferromagnetic XXZ chains with coupling J > 0 and anisotropy 0<Δ ≤slant 1 , we describe how the block-spin renormalization procedure preserving the SU q (2) symmetry introduced by Martin-Delgado and Sierra (1996 Phys. Rev. Lett. 76 1146) can be reformulated as the translation-invariant scale-invariant tree-tensor-state of the smallest dimension that is compatible with the quantum symmetries of the model. The properties of this tree-tensor-state are studied in detail via the ground-state energy, the magnetizations and the staggered magnetizations, as well as the Shannon-Renyi entropies characterizing the multifractality of the components of the wave function.
Thermodynamic limit of particle-hole form factors in the massless XXZ Heisenberg chain
Energy Technology Data Exchange (ETDEWEB)
Kitanine, N. [Univ. de Bourgogne (France). IMB, UMR 5584 du CNRS; Kozlowski, K.K. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Maillet, J.M.; Terras, V. [ENS Lyon (France). UMR 5672 du CNRS, Lab. de Physique; Slavnov, N.A. [Steklov Mathematical Inst., Moscow (Russian Federation)
2011-03-15
We study the thermodynamic limit of the particle-hole form factors of the XXZ Heisenberg chain in the massless regime. We show that, in this limit, such form factors decrease as an explicitly computed power-law in the system size. Moreover, the corresponding amplitudes can be obtained as a product of a ''smooth'' and a ''discrete'' part: the former depends continuously on the rapidities of the particles and holes, whereas the latter has an additional explicit dependence on the set of integer numbers that label each excited state in the associated logarithmic Bethe equations. We also show that special form factors corresponding to zero-energy excitations lying on the Fermi surface decrease as a power-law in the system size with the same critical exponents as in the longdistance asymptotic behavior of the related two-point correlation functions. The methods we develop in this article are rather general and can be applied to other massless integrable models associated to the six-vertex R-matrix and having determinant representations for their form factors. (orig.)
q-Power function over q-commuting variables and deformed XXX, XXZ chains
International Nuclear Information System (INIS)
Khoroshkin, S.M.; Stolin, A.A.; Tolstoy, V.N.
2001-01-01
Certain functional identifies for the Gauss q-power function of a sum of q-commuting variables are found. Then these identifies are used to obtain two-parameter twists of the quantum affine algebra U q (sl 2 ) and of the Yangian Y(sl 2 ). The corresponding deformed trigonometric and rational quantum R matrices, which then are used in the computation of deformed XXX and XXZ Hamiltonians [ru
Impurity modes in the one-dimensional XXZ Heisenberg model
International Nuclear Information System (INIS)
Sousa, J.M.; Leite, R.V.; Landim, R.R.; Costa Filho, R.N.
2014-01-01
A Green's function formalism is used to calculate the energy of impurity modes associated with one and/or two magnetic impurities in the one-dimensional Heisenberg XXZ magnetic chain. The system can be tuned from the Heisenberg to the Ising model varying a parameter λ. A numerical study is performed showing two types of localized modes (s and p). The modes depend on λ and the degeneracy of the acoustic modes is broken.
On the physical part of the factorized correlation functions of the XXZ chain
International Nuclear Information System (INIS)
Boos, Herman; Goehmann, Frank
2009-01-01
It was recently shown by Jimbo et al (2008 arXiv:0811.0439) that the correlation functions of a generalized XXZ chain associated with an inhomogeneous six-vertex model with a disorder parameter α and with arbitrary inhomogeneities on the horizontal lines factorize and can all be expressed in terms of only two functions ρ and ω. Here we approach the description of the same correlation functions and, in particular, of the function ω from a different direction. We start from a novel multiple integral representation for the density matrix of a finite chain segment of length m in the presence of a disorder field α. We explicitly factorize the integrals for m = 2. Based on this, we present an alternative description of the function ω in terms of the solutions of certain linear and nonlinear integral equations. We then prove directly that the two definitions of ω describe the same function. The definition in the work of Jimbo et al (2008 arXiv:0811.0439) was crucial for the proof of the factorization. The definition given here together with the known description of ρ in terms of the solutions of nonlinear integral equations is useful for performing, e.g., the Trotter limit in the finite temperature case, or for obtaining numerical results for the correlation functions at short distances. We also address the issue of the construction of an exponential form of the density matrix for finite α.
Quasilocal conservation laws in XXZ spin-1/2 chains: Open, periodic and twisted boundary conditions
Directory of Open Access Journals (Sweden)
Tomaž Prosen
2014-09-01
Full Text Available A continuous family of quasilocal exact conservation laws is constructed in the anisotropic Heisenberg (XXZ spin-1/2 chain for periodic (or twisted boundary conditions and for a set of commensurate anisotropies densely covering the entire easy plane interaction regime. All local conserved operators follow from the standard (Hermitian transfer operator in fundamental representation (with auxiliary spin s=1/2, and are all even with respect to a spin flip operation. However, the quasilocal family is generated by differentiation of a non-Hermitian highest weight transfer operator with respect to a complex auxiliary spin representation parameter s and includes also operators of odd parity. For a finite chain with open boundaries the time derivatives of quasilocal operators are not strictly vanishing but result in operators localized near the boundaries of the chain. We show that a simple modification of the non-Hermitian transfer operator results in exactly conserved, but still quasilocal operators for periodic or generally twisted boundary conditions. As an application, we demonstrate that implementing the new exactly conserved operator family for estimating the high-temperature spin Drude weight results, in the thermodynamic limit, in exactly the same lower bound as for almost conserved family and open boundaries. Under the assumption that the bound is saturating (suggested by agreement with previous thermodynamic Bethe ansatz calculations we propose a simple explicit construction of infinite time averages of local operators such as the spin current.
Heisenberg spin-1/2 XXZ chain in the presence of electric and magnetic fields
Thakur, Pradeep; Durganandini, P.
2018-02-01
We study the interplay of electric and magnetic order in the one-dimensional Heisenberg spin-1/2 XXZ chain with large Ising anisotropy in the presence of the Dzyaloshinskii-Moriya (DM) interaction and with longitudinal and transverse magnetic fields, interpreting the DM interaction as a coupling between the local electric polarization and an external electric field. We obtain the ground state phase diagram using the density matrix renormalization group method and compute various ground state quantities like the magnetization, staggered magnetization, electric polarization and spin correlation functions, etc. In the presence of both longitudinal and transverse magnetic fields, there are three different phases corresponding to a gapped Néel phase with antiferromagnetic (AF) order, gapped saturated phase, and a critical incommensurate gapless phase. The external electric field modifies the phase boundaries but does not lead to any new phases. Both external magnetic fields and electric fields can be used to tune between the phases. We also show that the transverse magnetic field induces a vector chiral order in the Néel phase (even in the absence of an electric field) which can be interpreted as an electric polarization in a direction parallel to the AF order.
The role of the central element in the quantum algebra underlying the twisted XXZ chain
International Nuclear Information System (INIS)
Monteiro, M.R.; Roditi, I.; Rodrigues, L.M.C.S.; Sciuto, S.
1995-03-01
The relationship among the XXZ Heisenberg model and three models obtained from it by various transformations is studied. In particular, it is emphasized the role of a non trivial central element t Z in the underlying algebra and its relationship with the twisted boundary conditions, S +- N+1 = t +-N S +- 1 . (author). 18 refs
Ming, Fei; Wang, Dong; Shi, Wei-Nan; Huang, Ai-Jun; Sun, Wen-Yang; Ye, Liu
2018-04-01
The uncertainty principle is recognized as an elementary ingredient of quantum theory and sets up a significant bound to predict outcome of measurement for a couple of incompatible observables. In this work, we develop dynamical features of quantum memory-assisted entropic uncertainty relations (QMA-EUR) in a two-qubit Heisenberg XXZ spin chain with an inhomogeneous magnetic field. We specifically derive the dynamical evolutions of the entropic uncertainty with respect to the measurement in the Heisenberg XXZ model when spin A is initially correlated with quantum memory B. It has been found that the larger coupling strength J of the ferromagnetism ( J 0 ) chains can effectively degrade the measuring uncertainty. Besides, it turns out that the higher temperature can induce the inflation of the uncertainty because the thermal entanglement becomes relatively weak in this scenario, and there exists a distinct dynamical behavior of the uncertainty when an inhomogeneous magnetic field emerges. With the growing magnetic field | B | , the variation of the entropic uncertainty will be non-monotonic. Meanwhile, we compare several different optimized bounds existing with the initial bound proposed by Berta et al. and consequently conclude Adabi et al.'s result is optimal. Moreover, we also investigate the mixedness of the system of interest, dramatically associated with the uncertainty. Remarkably, we put forward a possible physical interpretation to explain the evolutionary phenomenon of the uncertainty. Finally, we take advantage of a local filtering operation to steer the magnitude of the uncertainty. Therefore, our explorations may shed light on the entropic uncertainty under the Heisenberg XXZ model and hence be of importance to quantum precision measurement over solid state-based quantum information processing.
Quantum discord and quantum phase transition in spin chains
Dillenschneider, Raoul
2008-01-01
Quantum phase transitions of the transverse Ising and antiferromagnetic XXZ spin S=1/2 chains are studied using quantum discord. Quantum discord allows the measure of quantum correlations present in many-body quantum systems. It is shown that the amount of quantum correlations increases close to the critical points. The observations are in agreement with the information provided by the concurrence which measures the entanglement of the many-body system.
International Nuclear Information System (INIS)
Hauke, Philipp; Cucchietti, Fernando M; Lewenstein, Maciej; Mueller-Hermes, Alexander; Banuls, Mari-Carmen; Ignacio Cirac, J
2010-01-01
Systems with long-range interactions show a variety of intriguing properties: they typically accommodate many metastable states, they can give rise to spontaneous formation of supersolids, and they can lead to counterintuitive thermodynamic behavior. However, the increased complexity that comes with long-range interactions strongly hinders theoretical studies. This makes a quantum simulator for long-range models highly desirable. Here, we show that a chain of trapped ions can be used to quantum simulate a one-dimensional (1D) model of hard-core bosons with dipolar off-site interaction and tunneling, equivalent to a dipolar XXZ spin-1/2 chain. We explore the rich phase diagram of this model in detail, employing perturbative mean-field theory, exact diagonalization and quasi-exact numerical techniques (density-matrix renormalization group and infinite time-evolving block decimation). We find that the complete devil's staircase-an infinite sequence of crystal states existing at vanishing tunneling-spreads to a succession of lobes similar to the Mott lobes found in Bose-Hubbard models. Investigating the melting of these crystal states at increased tunneling, we do not find (contrary to similar 2D models) clear indications of supersolid behavior in the region around the melting transition. However, we find that inside the insulating lobes there are quasi-long-range (algebraic) correlations, as opposed to models with nearest-neighbor tunneling, that show exponential decay of correlations.
Droplet localization in the random XXZ model and its manifestations
Elgart, A.; Klein, A.; Stolz, G.
2018-01-01
We examine many-body localization properties for the eigenstates that lie in the droplet sector of the random-field spin- \\frac 1 2 XXZ chain. These states satisfy a basic single cluster localization property (SCLP), derived in Elgart et al (2018 J. Funct. Anal. (in press)). This leads to many consequences, including dynamical exponential clustering, non-spreading of information under the time evolution, and a zero velocity Lieb-Robinson bound. Since SCLP is only applicable to the droplet sector, our definitions and proofs do not rely on knowledge of the spectral and dynamical characteristics of the model outside this regime. Rather, to allow for a possible mobility transition, we adapt the notion of restricting the Hamiltonian to an energy window from the single particle setting to the many body context.
Long-range interactions in antiferromagnetic quantum spin chains
Bravo, B.; Cabra, D. C.; Gómez Albarracín, F. A.; Rossini, G. L.
2017-08-01
We study the role of long-range dipolar interactions on antiferromagnetic spin chains, from the classical S →∞ limit to the deep quantum case S =1 /2 , including a transverse magnetic field. To this end, we combine different techniques such as classical energy minima, classical Monte Carlo, linear spin waves, bosonization, and density matrix renormalization group (DMRG). We find a phase transition from the already reported dipolar ferromagnetic region to an antiferromagnetic region for high enough antiferromagnetic exchange. Thermal and quantum fluctuations destabilize the classical order before reaching magnetic saturation in both phases, and also close to zero field in the antiferromagnetic phase. In the extreme quantum limit S =1 /2 , extensive DMRG computations show that the main phases remain present with transition lines to saturation significatively shifted to lower fields, in agreement with the bosonization analysis. The overall picture maintains a close analogy with the phase diagram of the anisotropic XXZ spin chain in a transverse field.
International Nuclear Information System (INIS)
Kudo, Kazue; Nakamura, Katsuhiro
2009-01-01
We investigate dynamical stability of the ground state against a time-periodic and spatially-inhomogeneous magnetic field for finite quantum XXZ spin chains. We use the survival probability as a measure of stability and demonstrate that it decays as P(t) ∝ t -1/2 under a certain condition. The dynamical properties should also be related to the level statistics of the XXZ spin chains with a constant spatially-inhomogeneous magnetic field. The level statistics depends on the anisotropy parameter and the field strength. We show how the survival probability depends on the anisotropy parameter, the strength and frequency of the field.
Design Principles for Closed Loop Supply Chains
H.R. Krikke (Harold); C.P. Pappis (Costas); G.T. Tsoulfas; J.M. Bloemhof-Ruwaard (Jacqueline)
2001-01-01
textabstractIn this paper we study design principles for closed loop supply chains. Closed loop supply chains aim at closing material flows thereby limiting emission and residual waste, but also providing customer service at low cost. We study 'traditional' and 'new' design principles known in the
Closed Loop Supply Chains for Sustainable Mass Customization
DEFF Research Database (Denmark)
Nielsen, Kjeld; Brunø, Thomas Ditlev
2013-01-01
Closed loop supply chains reducing waste, energy consumption and natural resource depletion which all contribute to more sustainable production and products. For mass customization however, the challenges of closed loop supply chains are emphasized by the large variety of inbound end-of-life prod......Closed loop supply chains reducing waste, energy consumption and natural resource depletion which all contribute to more sustainable production and products. For mass customization however, the challenges of closed loop supply chains are emphasized by the large variety of inbound end...
Magnetoelectric effects in the spin-1/2 XXZ model with Dzyaloshinskii-Moriya interaction
International Nuclear Information System (INIS)
Thakur, Pradeep; Durganandini, P.
2015-01-01
We study the 1D spin-1/2 XXZ chain in the presence of the Dzyaloshinskii-Moriya (D-M) interaction and with longitudinal and transverse magnetic fields. We assume the spin-current mechanism of Katsura-Nagaosa-Balatsky at play and interpret the D-M interaction as a coupling between the local electric polarization and an external electric field. We study the interplay of electric and magnetic order in the ground state using the numerical density matrix renormalization group(DMRG) method. Specifically, we investigate the dependences of the magnetization and electric polarization on the external electric and magnetic fields. We find that for transverse magnetic fields, there are two different regimes of polarization while for longitudinal magnetic fields, there are three different regimes of polarization. The different regimes can be tuned by the external magnetic fields
Directory of Open Access Journals (Sweden)
Stefan Seuring
2011-04-01
Full Text Available Supply chain management and closed-loop supply chain management (CLSCM have developed into established concepts in recent years. The related material cycles and product returns form an important part of all related processes with high potential for reducing environmental burden. The paper proposes a framework for (environmentally triggered closed-loop supply chain management, spanning three different levels: the societal or governance, the chain and the actor level. Within each level, a set of activities or processes can be identified. Taken together, the levels allow a comprehensive analysis of a closed-loop supply chain system. This is illustrated building on two case studies in the textile and apparel industry, where closed-loop supply chains have been designed to take specific apparel products back. The case studies are analyzed against all three levels and allow exemplification of related challenges and interrelations among the three levels. The three levels contribute to the further comprehension of the multiple issues having to be taken into account for successfully implementing closed-loop supply chains.
Influence of magnetic field on swap operation in Heisenberg XXZ model
Energy Technology Data Exchange (ETDEWEB)
Liu Jia [Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100083 (China); Zhang Guofeng, E-mail: gf1978zhang@buaa.edu.c [Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100083 (China); Chen Ziyu [Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100083 (China)
2009-05-01
Swap operation based on a two-qubit Heisenberg XXZ model under a uniform magnetic field in arbitrary direction and magnitude is investigated. It is shown that swap gate can be implemented on some conditions and its feasibility is established.
Influence of magnetic field on swap operation in Heisenberg XXZ model
International Nuclear Information System (INIS)
Liu Jia; Zhang Guofeng; Chen Ziyu
2009-01-01
Swap operation based on a two-qubit Heisenberg XXZ model under a uniform magnetic field in arbitrary direction and magnitude is investigated. It is shown that swap gate can be implemented on some conditions and its feasibility is established.
Reverse logistics and closed-loop supply chain
DEFF Research Database (Denmark)
Govindan, Kannan; Soleimani, Hamed; Kannan, Devika
2015-01-01
Based on environmental, legal, social, and economic factors, reverse logistics and closed-loop supply chain issues have attracted attention among both academia and practitioners. This attention is evident by the vast number of publications in scientific journals which have been published in recent...... years. Hence, a comprehensive literature review of recent and state-of-the-art papers is vital to draw a framework of the past, and to shed light on future directions. The aim of this paper is to review recently published papers in reverse logistic and closed-loop supply chain in scientific journals...
Chained learning architectures in a simple closed-loop behavioural context
DEFF Research Database (Denmark)
Kulvicius, Tomas; Porr, Bernd; Wörgötter, Florentin
2007-01-01
are very simple and consist of single learning unit. The current study is trying to solve this problem focusing on chained learning architectures in a simple closed-loop behavioural context. METHODS: We applied temporal sequence learning (Porr B and Wörgötter F 2006) in a closed-loop behavioural system...... where a driving robot learns to follow a line. Here for the first time we introduced two types of chained learning architectures named linear chain and honeycomb chain. We analyzed such architectures in an open and closed-loop context and compared them to the simple learning unit. CONCLUSIONS...
From closed-loop to sustainable suplly chains: the WEEE case
Quariguasi Frota Neto, J.; Walther, G.; Bloemhof, J.M.; Nunen, van J.A.E.E.; Spengler, T.
2010-01-01
The primary objective of closed-loop supply chains (CLSC) is to improve the maximum economic benefit from end-of-use products. Nevertheless, the literature within this stream of research advocates that closing the loop also helps to mitigate the undesirable environmental footprint of supply chains.
Drivers of close supply chain collaboration: one size fits all?
de Leeuw, S.L.J.M.; Fransoo, J.C.
2009-01-01
Purpose - The purpose of this paper is to investigate the antecedents of close supply chain collaboration and to develop a multi-variable conceptual model of factors that drive the need for close supply chain collaboration. Design/methodology/approach - A multi-variable conceptual model is developed
Drivers of close supply chain collaboration : one size fits all?
Leeuw, de S.L.J.M.; Fransoo, J.C.
2009-01-01
Purpose – The purpose of this paper is to investigate the antecedents of close supply chain collaboration and to develop a multi-variable conceptual model of factors that drive the need for close supply chain collaboration. Design/methodology/approach – A multi-variable conceptual model is developed
SUSY field theories in higher dimensions and integrable spin chains
International Nuclear Information System (INIS)
Gorsky, A.; Gukov, S.; Mironov, A.
1998-01-01
Five- and six-dimensional SUSY gauge theories, with one or two compactified directions, are discussed. The 5d theories with the matter hypermultiplets in the fundamental representation are associated with the twisted XXZ spin chain, while the group product case with bi-fundamental matter corresponds to the higher rank spin chains. The Riemann surfaces for 6d theories with fundamental matter and two compact directions are proposed to correspond to the XYZ spin chain based on the Sklyanin algebra. We also discuss the obtained results within the brane and geometrical engineering frameworks and explain the relation to the toric diagrams. (orig.)
Effect of anisotropy on the entanglement of quantum states in a spin chain
Kartsev, PF; Kashurnikov, VA
2004-01-01
The effect of the anisotropy of the interaction of a spin chain in the XXZ Heisenberg model on the concurrence of the states of neighboring sites is studied. When anisotropy increases, the maximum concurrence in a magnetic field increases above the value reached in the absence of the field. The
Production planning and control of closed-loop supply chains
K. Inderfurth (Karl); R.H. Teunter (Ruud)
2001-01-01
textabstractMore and more supply chains emerge that include a return flow of materials. Many original equipment manufacturers are nowadays engaged in the remanufacturing business. In many process industries, production defectives and by-products are reworked. These closed-loop supply chains deserve
On spin chains and field theories
International Nuclear Information System (INIS)
Roiban, Radu
2004-01-01
We point out that the existence of global symmetries in a field theory is not an essential ingredient in its relation with an integrable model. We describe an obvious construction which, given an integrable spin chain, yields a field theory whose 1-loop scale transformations are generated by the spin chain hamiltonian. We also identify a necessary condition for a given field theory to be related to an integrable spin chain. As an example, we describe an anisotropic and parity-breaking generalization of the XXZ Heisenberg spin chain and its associated field theory. The system has no nonabelian global symmetries and generally does not admit a supersymmetric extension without the introduction of more propagating bosonic fields. For the case of a 2-state chain we find the spectrum and the eigenstates. For certain values of its coupling constants the field theory associated to this general type of chain is the bosonic sector of the q-deformation of N = 4 SYM theory. (author)
Rojas, M.; de Souza, S. M.; Rojas, Onofre
2017-02-01
The quantum teleportation plays an important role in quantum information process, in this sense, the quantum entanglement properties involving an infinite chain structure is quite remarkable because real materials could be well represented by an infinite chain. We study the teleportation of an entangled state through a couple of quantum channels, composed by Heisenberg dimers in an infinite Ising-Heisenberg diamond chain, the couple of chains are considered sufficiently far away from each other to be ignored the any interaction between them. To teleporting a couple of qubits through the quantum channel, we need to find the average density operator for Heisenberg spin dimers, which will be used as quantum channels. Assuming the input state as a pure state, we can apply the concept of fidelity as a useful measurement of teleportation performance of a quantum channel. Using the standard teleportation protocol, we have derived an analytical expression for the output concurrence, fidelity, and average fidelity. We study in detail the effects of coupling parameters, external magnetic field and temperature dependence of quantum teleportation. Finally, we explore the relations between entanglement of the quantum channel, the output entanglement and the average fidelity of the system. Through a kind of phase diagram as a function of Ising-Heisenberg diamond chain model parameters, we illustrate where the quantum teleportation will succeed and a region where the quantum teleportation could fail.
Rationale for evaluating a closed food chain for space habitats
Modell, M.; Spurlock, J. M.
1980-01-01
Closed food cycles for long duration space flight and space habitation are examined. Wash water for a crew of six is economically recyclable after a week, while a total closed loop water system is effective only if the stay exceeds six months' length. The stoichiometry of net plant growth is calculated and it is shown that the return of urine, feces, and inedible plant parts to the food chain, along with the addition of photosynthesis, closes the food chain loop. Scenarios are presented to explore the technical feasibility of achieving a closed loop system. An optimal choice of plants is followed by processing, waste conversion, equipment specifications, and control requirements, and finally, cost-effectiveness.
A review of reverse logistics and closed-loop supply chains
DEFF Research Database (Denmark)
Govindan, Kannan; Soleimani, Hamed
2016-01-01
Today, the task of developing reverse logistics and closed-loop supply chains in both developed and developing industries is accepted as a vital need in our societies. The growing interest in reverse issues can be clearly seen in the large number of publications, especially the ones that consider...... case studies in various industries. Based on its missions, Journal of Cleaner Production (JCP) is one of the most active journals in this field. Therefore, a comprehensive review is undertaken of the publications in the field of reverse logistics and closed-loop supply chains; the selection process...... December 2014 have been selected and reviewed. The selected papers are then analyzed based on their content and the appropriate developed categories. The results clarify the main trends in reverse logistics and closed-loop supply chain subjects for the Journal of Cleaner Production and the evaluations...
Directory of Open Access Journals (Sweden)
Phillip Weinberg, Marin Bukov
2017-02-01
Full Text Available We present a new open-source Python package for exact diagonalization and quantum dynamics of spin(-photon chains, called QuSpin, supporting the use of various symmetries in 1-dimension and (imaginary time evolution for chains up to 32 sites in length. The package is well-suited to study, among others, quantum quenches at finite and infinite times, the Eigenstate Thermalisation hypothesis, many-body localisation and other dynamical phase transitions, periodically-driven (Floquet systems, adiabatic and counter-diabatic ramps, and spin-photon interactions. Moreover, QuSpin's user-friendly interface can easily be used in combination with other Python packages which makes it amenable to a high-level customisation. We explain how to use QuSpin using four detailed examples: (i Standard exact diagonalisation of XXZ chain (ii adiabatic ramping of parameters in the many-body localised XXZ model, (iii heating in the periodically-driven transverse-field Ising model in a parallel field, and (iv quantised light-atom interactions: recovering the periodically-driven atom in the semi-classical limit of a static Hamiltonian.
Thermodynamic Bethe Ansatz for the Spin-1/2 Staggered XXZ- Model
Mkhitaryan, V. V.; Sedrakyan, A. G.
2003-01-01
We develop the technique of Thermodynamic Bethe Ansatz to investigate the ground state and the spectrum in the thermodynamic limit of the staggered $XXZ$ models proposed recently as an example of integrable ladder model. This model appeared due to staggered inhomogeneity of the anisotropy parameter $\\Delta$ and the staggered shift of the spectral parameter. We give the structure of ground states and lowest lying excitations in two different phases which occur at zero temperature.
Sustainable Rent-Based Closed-Loop Supply Chain for Fashion Products
Directory of Open Access Journals (Sweden)
Zhi-Hua Hu
2014-10-01
Full Text Available The textile and clothing industry generates much pollution and consumes a large amount of resources. Improper uses and disposal of clothing products make the problems much more severe. Fast fashion products shorten the valid lifecycle and generate more waste than regular clothing products. Considering the features of fashion products, a system of a rent-based closed-loop supply chain is developed to improve the sustainability of fashion products. The supply chain processes (fashion design and manufacturing, laundry, logistics and disposal, the operations management issues (inventory management, closed-loop logistics, human-clothing matching, booking system and the rental pricing and the sustainability promotion aspects (customization, responsive system, culture and policy aspects are investigated by devising sustainable strategies. The rationalities of the developed system and strategies are reviewed and elucidated in detail. The results may contribute to building sustainable closed-loop fashion supply chains, the related information systems and operational and managerial mechanisms.
Closed-loop Supply Chain as an Agent of Sustainable Development
Directory of Open Access Journals (Sweden)
Shu-San Gan
2015-06-01
Full Text Available Sustainability has recently become an important issue which received growing attentions from government, society, industries as well as academia. There have been concerns on relatively rapid growth in population and increased quality of life despite limited natural resources and landfill capacity. Closed-loop Supply Chain (CLSC is one of many approaches to mitigate the abovementioned disproportion. This article aims to study closed-loop supply chain by explaining the definition, description, pros and contras, relevance, case studies from literature, and potential research; such that its role as an agent of sustainable development can be recognized.
Self-similar spectral structures and edge-locking hierarchy in open-boundary spin chains
International Nuclear Information System (INIS)
Haque, Masudul
2010-01-01
For an anisotropic Heisenberg (XXZ) spin chain, we show that an open boundary induces a series of approximately self-similar features at different energy scales, high up in the eigenvalue spectrum. We present a nonequilibrium phenomenon related to this fractal structure, involving states in which a connected block near the edge is polarized oppositely to the rest of the chain. We show that such oppositely polarized blocks can be 'locked' to the edge of the spin chain and that there is a hierarchy of edge-locking effects at various orders of the anisotropy. The phenomenon enables dramatic control of quantum-state transmission and magnetization control.
Entanglement and local extremes at an infinite-order quantum phase transition
International Nuclear Information System (INIS)
Rulli, C. C.; Sarandy, M. S.
2010-01-01
The characterization of an infinite-order quantum phase transition (QPT) by entanglement measures is analyzed. To this aim, we consider two closely related solvable spin-1/2 chains, namely, the Ashkin-Teller and the staggered XXZ models. These systems display a distinct pattern of eigenstates but exhibit the same thermodynamics, that is, the same energy spectrum. By performing exact diagonalization, we investigate the behavior of pairwise and block entanglement in the ground state of both models. In contrast with the XXZ chain, we show that pairwise entanglement fails in the characterization of the infinite-order QPT in the Ashkin-Teller model, although it can be achieved by analyzing the distance of the pair state from the separability boundary. Concerning block entanglement, we show that both XXZ and Ashkin-Teller models exhibit identical von Neumann entropies as long as a suitable choice of blocks is performed. Entanglement entropy is then shown to be able to identify the quantum phase diagram, even though its local extremes (either maximum or minimum) may also appear in the absence of any infinite-order QPT.
Beyond Waste Reduction: Creating Value with Information Systems in Closed-Loop Supply Chains
O.R. Koppius (Otto); O. Ozdemir (Oznur); E.A. van der Laan (Erwin)
2011-01-01
textabstractWe study the role of information systems in enabling closed-loop supply chains. Past research in green IS and closed-loop supply chains has shown that it can result in substantial cost savings and waste reduction. We complement this research by showing that the effects are more than
Statistically interacting quasiparticles in Ising chains
International Nuclear Information System (INIS)
Lu Ping; Vanasse, Jared; Piecuch, Christopher; Karbach, Michael; Mueller, Gerhard
2008-01-01
The exclusion statistics of two complementary sets of quasiparticles, generated from opposite ends of the spectrum, are identified for Ising chains with spin s = 1/2, 1. In the s = 1/2 case the two sets are antiferromagnetic domain walls (solitons) and ferromagnetic domains (strings). In the s = 1 case they are soliton pairs and nested strings, respectively. The Ising model is equivalent to a system of two species of solitons for s = 1/2 and to a system of six species of soliton pairs for s = 1. Solitons exist on single bonds but soliton pairs may be spread across many bonds. The thermodynamics of a system of domains spanning up to M lattice sites is amenable to exact analysis and shown to become equivalent, in the limit M → ∞, to the thermodynamics of the s = 1/2 Ising chain. A relation is presented between the solitons in the Ising limit and the spinons in the XX limit of the s = 1/2 XXZ chain
Magnetic properties of S=l/2 antiferromagnetic XXZ model on the Shastry-Sutherland lattices
International Nuclear Information System (INIS)
Suzuki, Takafumi; Tomita, Yusuke; Kawashima, Naoki
2010-01-01
We study magnetic properties of the S=l/2 Ising-like XXZ model on the Shastry-Sutherland lattices considering the effect of long range interactions. By performing quantum Monte Carlo simulations, we find that magnetization plateau phases appear at one-half and one-third of the saturation magnetization. We also study the finite temperature transition to the magnetic plateau phases and discuss the universality class of the transition.
Storing quantum information in XXZ spin rings with periodically time-controlled interactions
International Nuclear Information System (INIS)
Giampaolo, S M; Illuminati, F; Mazzarella, G
2005-01-01
We introduce a general scheme to realize massive quantum memories in simple systems of interacting qubits. Such systems are described by spin rings with XXZ intersite couplings of suitably time-periodically controlled amplitudes. We show that initially localized excitations undergo perfect periodic revivals, allowing for the simultaneous storage of arbitrary sets of different local states. This novel approach to the problem of storing quantum information hints at a new way to control and suppress the effect of decoherence on a quantum computer realized in a system with nonvanishing interactions between the constituent qubits
Storing quantum information in XXZ spin rings with periodically time-controlled interactions
Energy Technology Data Exchange (ETDEWEB)
Giampaolo, S M; Illuminati, F; Mazzarella, G [Dipartimento di Fisica ' E. R. Caianiello' , Universita di Salerno, INFM UdR di Salerno, INFN Sezione di Napoli, Gruppo Collegato di Salerno, Via S. Allende, 84081 Baronissi, SA (Italy)
2005-10-01
We introduce a general scheme to realize massive quantum memories in simple systems of interacting qubits. Such systems are described by spin rings with XXZ intersite couplings of suitably time-periodically controlled amplitudes. We show that initially localized excitations undergo perfect periodic revivals, allowing for the simultaneous storage of arbitrary sets of different local states. This novel approach to the problem of storing quantum information hints at a new way to control and suppress the effect of decoherence on a quantum computer realized in a system with nonvanishing interactions between the constituent qubits.
Robust environmental closed-loop supply chain design under uncertainty
International Nuclear Information System (INIS)
MA, Ruimin; YAO, Lifei; JIN, Maozhu; REN, Peiyu; LV, Zhihan
2016-01-01
With the fast developments in product remanufacturing to improve economic and environmental performance, an environmental closed-loop supply (ECLSC) chain is important for enterprises' competitiveness. In this paper, a robust ECLSC network is investigated which includes multiple plants, collection centers, demand zones, and products, and consists of both forward and reverse supply chains. First, a robust multi-objective mixed integer nonlinear programming model is proposed to deal with ECLSC considering two conflicting objectives simultaneously, as well as the uncertain nature of the supply chain. Cost parameters of the supply chain and demand fluctuations are subject to uncertainty. The first objective function aims to minimize the economical cost and the second objective function is to minimize the environmental influence. Then, the proposed model is solved as a single-objective mixed integer programming model applying the LP-metrics method. Finally, numerical example has been presented to test the model. The results indicate that the proposed model is applicable in practice.
Coordinated Resolved Motion Control of Dual-Arm Manipulators with Closed Chain
Directory of Open Access Journals (Sweden)
Tianliang Liu
2016-05-01
Full Text Available When applied to some tasks, such as payload handling, assembling, repairing and so on, the two arms of a humanoid robot will form a closed kinematic chain. It makes the motion planning and control for dual-arm coordination very complex and difficult. In this paper, we present three types of resolved motion control methods for a humanoid robot during coordinated manipulation. They are, respectively, position-level, velocity-level and acceleration-level resolved motion control methods. The desired pose, velocity and acceleration of each end-effector are then resolved according to the desired motion of the payload and the constraints on the closed-chain system without consideration of the internal force. Corresponding to the three cases above, the joint variables of each arm are then calculated using the inverse kinematic equations, at position-level, velocity-level or acceleration-level. Finally, a dynamic modelling and simulation platform is established based on ADAMS and Matlab software. The proposed methods are verified by typical cases. The simulation results show that the proposed control strategy can realize the dual-arm coordinated operation and the internal force of the closed chain during the operation is controlled in a reasonable range at the same time.
Creating integral value for stakeholders in closed loop supply chains
Schenkel, Maren; Krikke, Harold; Caniëls, Marjolein CJ; van der Laan, Erwin
This paper contributes to the existing literature by researching integral value creation in closed loop supply chains (CLSCs). We distinguish between multiple types of business value, strategic success factors, and multiple groups of stakeholders that affect and are affected by CLSC activities. To
A framework for closed-loop supply chains of reusable articles
R. Carrasco-Gallego (Ruth); E. Ponce-Cueto (Eva); R. Dekker (Rommert)
2009-01-01
textabstractReuse practices contribute to the environmental and economical sustainability of production and distribution systems. Surprisingly, reuse closed-loop supply chains (CLSC) have not been widely researched for the moment. In this paper, we explore the scientific literature on reuse and we
Different Subsidies’ Impact on equilibrium decision-making of closed-loop supply chain
Directory of Open Access Journals (Sweden)
Liurui Deng
2014-10-01
Full Text Available Purpose: An electronic product recycling not only needs the waste treatment company, but also involves recycler and remanufacturer. It is significance for increasing subsidy modes and promoting waste recycling to research the effect of government subsidies for recycler and remanufacturer on the equilibrium of closed-loop supply chain. Approach: In view of service competition, we build a Stackelberg model which contains an original manufacturer, a recycler and remanufacturer and further obtain the equilibrium decision of closed-loop supply chain. Based on this strategy model, we analyze how two different subsidies to utilization rate of raw materials, the service level and the demand of product affect on the terminal decision. Findings: We compared the two different subsidy ways in closed-loop supply chain. Subsidy to utilization rate of raw materials has no effect on the whole market demand for electronic product; and subsidy on utilization rate of raw materials has no effect on the whole market demand for electronic product. Research implications: Under the conditions in which government can observe the information of raw material utility and remanufacturing service level, if government decides to expand the market size, it could subsidize remanufacturer for different service level; Under the conditions in which government can observe the information of raw material utility and remanufacturing service level, if government want to improve utilization rate of raw materials, stimulate sustainable development of industries of electronic product, it can subsidizes recycler based on different utilization rate of raw materials. Value: We analyzed the closed-loop supply chain equilibrium, compared the effects on it under different subsidy mechanism and offered some advises in order to provide scientific support to promote electronic products recycling.
Modeling and performance analysis of a closed-loop supply chain using first-order hybrid Petri nets
Directory of Open Access Journals (Sweden)
Imane Outmal
2016-05-01
Full Text Available Green or closed-loop supply chain had been the focus of many manufacturers during the last decade. The application of closed-loop supply chain in today’s manufacturing is not only due to growing environmental concerns and the recognition of its benefits in reducing greenhouse gas emissions, energy consumption, and meeting a more strict environmental regulations but it also offers economic competitive advantages if appropriately managed. First-order hybrid Petri nets represent a powerful graphical and mathematical formalism to map and analyze the dynamics of complex systems such as closed-loop supply chain networks. This article aims at illustrating the use of first-order hybrid Petri nets to model a closed-loop supply chain network and evaluate its operational, financial, and environmental performance measures under different management policies. Actual data from auto manufacturer in the United States are used to validate network’s performance under both tactical and strategic decision-making, namely, (1 tactical decision—production policies: increase of recovered versus new components and (2 strategic decision—closed-loop supply chain network structure: manufacturer internal recovery process or recovery process done by a third-party collection and recovery center. The work presented in this article is an extension of the use of first-order hybrid Petri nets as a modeling and performance analysis tool from supply chain to closed-loop supply chain. The modularity property of first-order hybrid Petri nets has been used in the modeling process, and the simulation and analysis of the modeled network are done in MATLAB® environment. The results of the experiments depict that first-order hybrid Petri nets are a powerful modeling and analysis formalism for closed-loop supply chain networks and can be further used as an efficient decision-making tool at both tactical and strategic levels. Unlike other researches on modeling supply chain
Temperature dependence of the NMR spin-lattice relaxation rate for spin-1/2 chains
Coira, E.; Barmettler, P.; Giamarchi, T.; Kollath, C.
2016-10-01
We use recent developments in the framework of a time-dependent matrix product state method to compute the nuclear magnetic resonance relaxation rate 1 /T1 for spin-1/2 chains under magnetic field and for different Hamiltonians (XXX, XXZ, isotropically dimerized). We compute numerically the temperature dependence of the 1 /T1 . We consider both gapped and gapless phases, and also the proximity of quantum critical points. At temperatures much lower than the typical exchange energy scale, our results are in excellent agreement with analytical results, such as the ones derived from the Tomonaga-Luttinger liquid (TLL) theory and bosonization, which are valid in this regime. We also cover the regime for which the temperature T is comparable to the exchange coupling. In this case analytical theories are not appropriate, but this regime is relevant for various new compounds with exchange couplings in the range of tens of Kelvin. For the gapped phases, either the fully polarized phase for spin chains or the low-magnetic-field phase for the dimerized systems, we find an exponential decrease in Δ /(kBT ) of the relaxation time and can compute the gap Δ . Close to the quantum critical point our results are in good agreement with the scaling behavior based on the existence of free excitations.
Gen2 RFID-Based System Framework for Resource Circulation in Closed-Loop Supply Chains
Directory of Open Access Journals (Sweden)
Young-woo Kim
2017-10-01
Full Text Available Product recycling has become a mandatory activity under extended producer responsibility. Therefore, it is important to operate a closed-loop supply chain that integrates sourcing, production, delivery, and recycling to achieve not only environmental sustainability, but also economic benefits. However, this goal is affected by chronic problems caused by uncertainties relating to the return timing, quantity, and quality of returned items. Many studies proved that information visibility could solve these problems. In this context, a system framework for closed-loop supply chain management is proposed that gathers real-time information within a supply chain and product lifecycle by using the Internet-of-Things, including radio frequency identification (RFID. Specifically, the most recent Gen2 RFID protocol, which provides new features to create new positive effects, is considered. Additionally, an information system is designed, including RFID tag encoding, which supports the operation of the proposed system. Finally, the lifecycle benefits are examined, such as counterfeit prevention, real-time monitoring and maintenance in the middle-of-life phase, and reverse process streamlining. The ultimate aim is to design a system that facilitates the profitable and environmentally friendly operation of the closed-loop supply chain.
Gorskova, Julija; Ortega, Edrion
2012-01-01
Abstract Problem There is a gap in the knowledge concerning reverse product flows due to a lack of research and empirical data in the field of reverse supply chain management in general. Furthermore, more research is needed to investigate the factors influencing the decision making process regarding the right reverse supply chain recovery option choice for companies in order to close the supply chain loop. Processing product returns has become a critical activity for organisations as the volu...
A Location-Inventory Problem in a Closed-Loop Supply Chain with Secondary Market Consideration
Directory of Open Access Journals (Sweden)
Hao Guo
2018-06-01
Full Text Available To design sustainable supply chain systems in today’s business environment, this paper studies a location-inventory problem in a closed-loop supply chain by considering the sales of new and used products in the primary and secondary markets, respectively. This problem is formulated as a mixed-integer nonlinear program to optimize facility location and inventory management decisions jointly, and the logistics flows between the two markets are modeled dynamically. To solve this problem efficiently, a new heuristic approach is also developed by introducing an effective adaptive mechanism into differential evolution. Finally, numerical experiments are presented to validate the solution approach and provide valuable managerial insight. This paper makes a meaningful contribution to the literature by incorporating the secondary market into the study of closed-loop supply chains, and practically, it is also greatly beneficial to improve the sustainability and efficiency of modern supply chains.
Closed-loop supply chain models with considering the environmental impact.
Mohajeri, Amir; Fallah, Mohammad
2014-01-01
Global warming and climate changes created by large scale emissions of greenhouse gases are a worldwide concern. Due to this, the issue of green supply chain management has received more attention in the last decade. In this study, a closed-loop logistic concept which serves the purposes of recycling, reuse, and recovery required in a green supply chain is applied to integrate the environmental issues into a traditional logistic system. Here, we formulate a comprehensive closed-loop model for the logistics planning considering profitability and ecological goals. In this way, we can achieve the ecological goal reducing the overall amount of CO2 emitted from journeys. Moreover, the profitability criterion can be supported in the cyclic network with the minimum costs and maximum service level. We apply three scenarios and develop problem formulations for each scenario corresponding to the specified regulations and investigate the effect of the regulation on the preferred transport mode and the emissions. To validate the models, some numerical experiments are worked out and a comparative analysis is investigated.
Closed-Loop Supply Chain Models with Considering the Environmental Impact
Directory of Open Access Journals (Sweden)
Amir Mohajeri
2014-01-01
Full Text Available Global warming and climate changes created by large scale emissions of greenhouse gases are a worldwide concern. Due to this, the issue of green supply chain management has received more attention in the last decade. In this study, a closed-loop logistic concept which serves the purposes of recycling, reuse, and recovery required in a green supply chain is applied to integrate the environmental issues into a traditional logistic system. Here, we formulate a comprehensive closed-loop model for the logistics planning considering profitability and ecological goals. In this way, we can achieve the ecological goal reducing the overall amount of CO2 emitted from journeys. Moreover, the profitability criterion can be supported in the cyclic network with the minimum costs and maximum service level. We apply three scenarios and develop problem formulations for each scenario corresponding to the specified regulations and investigate the effect of the regulation on the preferred transport mode and the emissions. To validate the models, some numerical experiments are worked out and a comparative analysis is investigated.
Quantum state transfer via a two-qubit Heisenberg XXZ spin model
Energy Technology Data Exchange (ETDEWEB)
Liu Jia; Zhang Guofeng [Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100083 (China); Chen Ziyu [Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing 100083 (China)], E-mail: chenzy@buaa.edu.cn
2008-04-14
Transfer of quantum states through a two-qubit Heisenberg XXZ spin model with a nonuniform magnetic field b is investigated by means of quantum theory. The influences of b, the spin exchange coupling J and the effective transfer time T=Jt on the fidelity have been studied for some different initial states. Results show that fidelity of the transferred state is determined not only by J, T and b but also by the initial state of this quantum system. Ideal information transfer can be realized for some kinds of initial states. We also found that the interactions of the z-component J{sub z} and uniform magnetic field B do not have any contribution to the fidelity. These results may be useful for quantum information processing.
Quantum state transfer via a two-qubit Heisenberg XXZ spin model
International Nuclear Information System (INIS)
Liu Jia; Zhang Guofeng; Chen Ziyu
2008-01-01
Transfer of quantum states through a two-qubit Heisenberg XXZ spin model with a nonuniform magnetic field b is investigated by means of quantum theory. The influences of b, the spin exchange coupling J and the effective transfer time T=Jt on the fidelity have been studied for some different initial states. Results show that fidelity of the transferred state is determined not only by J, T and b but also by the initial state of this quantum system. Ideal information transfer can be realized for some kinds of initial states. We also found that the interactions of the z-component J z and uniform magnetic field B do not have any contribution to the fidelity. These results may be useful for quantum information processing
Competitive closed-loop supply chain network design with price-dependent demands
DEFF Research Database (Denmark)
Rezapour, Shabnam; Farahani, Reza Zanjirani; Fahimnia, Behnam
2015-01-01
Abstract This paper presents a bi-level model for the strategic reverse network design (upper level) and tactical/operational planning (lower level) of a closed-loop single-period supply chain operating in a competitive environment with price-dependent market demand. An existing supply chain (SC...... for the supply of new and remanufactured products. The performance behaviors of both SCs are evaluated with specific focus placed on investigating the impacts of the strategic facility location decisions of the new SC on the tactical/operational transport and inventory decisions of the overall network. The bi...
Reverse and closed loop supply chain coordination by considering government role
DEFF Research Database (Denmark)
Heydari, Jafar; Govindan, Kannan; Jafari, Amin
2017-01-01
consumption by increasing customers’ willingness to return used products through offering a discount or a direct fee in exchange for bringing back EOL products. Afterward, the model is extended to consider a closed loop supply chain (CLSC). Quantity discounts and increasing fee contracts are proposed...
Integrating Closed-loop Supply Chains and Spare Parts Management at IBM
M. Fleischmann (Moritz); J.A.E.E. van Nunen (Jo); B. Graeve
2002-01-01
textabstractEver more companies are recognizing the benefits of closed-loop supply chains that integrate product returns into business operations. IBM has been among the pioneers seeking to unlock the value dormant in these resources. We report on a project exploiting product returns as a source of
A homomorphism between link and XXZ modules over the periodic Temperley–Lieb algebra
International Nuclear Information System (INIS)
Morin-Duchesne, Alexi; Saint-Aubin, Yvan
2013-01-01
We study finite loop models on a lattice wrapped around a cylinder. A section of the cylinder has N sites. We use a family of link modules over the periodic Temperley–Lieb algebra EPTL N (β,α) introduced by Martin and Saleur, and Graham and Lehrer. These are labeled by the numbers of sites N and of defects d, and extend the standard modules of the original Temperley–Lieb algebra. Besides the defining parameters β = u 2 + u −2 with u = e iλ/2 (weight of contractible loops) and α (weight of non-contractible loops), this family also depends on a twist parameter v that keeps track of how the defects wind around the cylinder. The transfer matrix T N (λ, ν) depends on the anisotropy ν and the spectral parameter λ that fixes the model. (The thermodynamic limit of T N is believed to describe conformal field theory of central charge c = 1 − 6λ 2 /(π(λ − π)).) The family of periodic XXZ Hamiltonians is extended to depend on this new parameter v, and the relationship between this family and the loop models is established. The Gram determinant for the natural bilinear form on these link modules is shown to factorize in terms of an intertwiner i-tilde N d between these link representations and the eigenspaces of S z of the XXZ models. This map is shown to be an isomorphism for generic values of u and v, and the critical curves in the plane of these parameters for which i-tilde N d fails to be an isomorphism are given. (paper)
Open versus closed kinetic chain exercises for patellar chondromalacia.
Bakhtiary, A H; Fatemi, E
2008-02-01
Conservative treatment of patellar chondromalacia has been the subject of several studies. One recommended treatment is a strengthening exercise of the quadriceps muscle, which may be performed in closed or open kinetic chains. This study was designed to compare the effect of straight leg raise (SLR) and semi-squat exercises on the treatment of patellar chondromalacia, which has not been done to date. 32 female university students with a diagnosis of patellar chondromalacia were randomly assigned to two experimental groups: SLR and semi-squat exercise. Before starting exercise protocols, Q angle, maximal isometric voluntary contraction force (MIVCF) of quadriceps, crepitation, circumference of thigh 5 and 10 cm above the patella and patellofemoral pain according to the visual analogue scale (VAS) were assessed. Both groups then followed a 3-week programme of quadriceps muscle strengthening exercises (SLR or semi-squat) starting with 20 exercises twice a day and increasing each session by 5 exercises every 2 days. All measurements were repeated at the end of each week and then again 2 weeks after the 3-week exercise programme. Reduced Q angle (mean differences (SD) 0.8 (0.3), p = 0.016) and crepitation (19.9 (8.5), p = 0.04), and an increase in the MIVCF of the quadriceps (15.8 (5.6), p = 0.01) and thigh circumference (1.5 (0.3), p = 0.001) were found in semi-squat group compared with SLR group. However, patellofemoral pain was decreased significantly in both groups. The results of this study indicate that semi-squat exercises (closed kinetic chain) are more effective than SLR exercise (open kinetic chain) in the treatment of patellar chondromalacia. More studies are needed to investigate the long-term effect of these types of exercise.
Analysis of a closed-kinematic chain robot manipulator
Nguyen, Charles C.; Pooran, Farhad J.
1988-01-01
Presented are the research results from the research grant entitled: Active Control of Robot Manipulators, sponsored by the Goddard Space Flight Center (NASA) under grant number NAG-780. This report considers a class of robot manipulators based on the closed-kinematic chain mechanism (CKCM). This type of robot manipulators mainly consists of two platforms, one is stationary and the other moving, and they are coupled together through a number of in-parallel actuators. Using spatial geometry and homogeneous transformation, a closed-form solution is derived for the inverse kinematic problem of the six-degree-of-freedom manipulator, built to study robotic assembly in space. Iterative Newton Raphson method is employed to solve the forward kinematic problem. Finally, the equations of motion of the above manipulators are obtained by employing the Lagrangian method. Study of the manipulator dynamics is performed using computer simulation whose results show that the robot actuating forces are strongly dependent on the mass and centroid locations of the robot links.
Spin-resolved entanglement spectroscopy of critical spin chains and Luttinger liquids
International Nuclear Information System (INIS)
Laflorencie, Nicolas; Rachel, Stephan
2014-01-01
Quantum critical chains are well-described and understood by virtue of conformal field theory. Still, the meaning of the real space entanglement spectrum—the eigenvalues of the reduced density matrix—of such systems remains elusive in general, even when there is an additional quantum number available such as the spin or particle number. In this paper, we explore in detail the properties and structure of the reduced density matrix of critical XXZ spin- (1/2) chains. We investigate the quantum/thermal correspondence between the reduced density matrix of a T = 0 pure quantum state and the thermal density matrix of an effective entanglement Hamiltonian. Using large scale DMRG and QMC simulations, we investigate the conformal structure of the spectra, the entanglement Hamiltonian, and temperature. We then introduce the notion of spin-resolved entanglement entropies, which display interesting scaling features. (paper)
Manufacturers’ Closed-Loop Orientation for Green Supply Chain Management
Directory of Open Access Journals (Sweden)
Shumin Liu
2017-02-01
Full Text Available The concept of green supply chain management (GSCM is still in its infancy and has been implemented only to a limited extent. Strategic orientation is an important factor affecting its implementation. No reliable and valid strategic orientation construct has been developed for greening a supply chain. This study proposes closed-loop orientation (CLO as the appropriate strategic orientation to implement GSCM practices successfully and develops a valid measurement of CLO. Data collected from 296 Chinese manufacturers were analyzed using the structural equation modeling method to examine the relationships among CLO, GSCM practice and environmental and economic performance. The results show that both CLO and GSCM have positive effects on the environmental performance and economic performance and that CLO positively impacts the level of implementation of GSCM. The results also show that GSCM completely mediates the relationships between CLO and environmental and economic performance.
Buffington, Jack; Peterson, Ray
2013-08-01
The purpose of this study is to conduct a supply chain material flow analysis (MFA) for the U.S. aluminum can market, consistent with studies conducted for the overall worldwide aluminum industry. A technical definition of the use of alloys 5182 and 3104 is conducted by metallurgists for use in the "aluminum can" MFA. Four propositions are created: technical, economic, and supply chain factors are as important to secondary aluminum recycling in an aluminum can as higher recycling rates (P1); the development of a unialloy aluminum can will increase reuse rates, but recycling rates must increase for this to happen (P2); a closed-loop aluminum can supply chain is not able to be fully realized in today's environment but is very useful for understanding improvement through both supply and demand (P3); and UBC supply can improve through a "voluntary deposit-refund system" approach (P4).
Collection effort and reverse channel choices in a closed-loop supply chain
DEFF Research Database (Denmark)
Govindan, Kannan; Liu, Liwen; Wang, Zongjun
2017-01-01
We investigate the pricing and reverse channel choice decision issues in a closed-loop supply chain, within which the original equipment manufacturer (OEM) sells the new and remanufactured products through a retailer, while collects used products (cores) via dual recycling channels. We consider...
System dynamics research of remanufacturing closed-loop supply chain dominated by the third party.
Miao, Shidi; Wang, Tengfei; Chen, Deyun
2017-04-01
With the rapid development of the electronic information industry in recent years, electronic products are being updated faster and faster, and e-waste recycling has become a common problem around the world. Firstly, this article contrasts recycling at home and abroad using the predicament of Midea Corp. Based on a closed-loop supply chain with the system dynamics method, a model is constructed and simulated. In this model, the collection point coverage rate is introduced to adjust the e-waste recycling rate dynamically. Aiming at a recycling mode dominated by the third party of the closed-loop supply chain, the article mainly discusses the impact on the sales rate and market share of the recycling model by third-party enterprises and compares the total revenue of all supply chains. Simulation results show that the model is more effective and optimal than the traditional recycling model.
Type-I integrable quantum impurities in the Heisenberg model
Energy Technology Data Exchange (ETDEWEB)
Doikou, Anastasia, E-mail: adoikou@upatras.gr
2013-12-21
Type-I quantum impurities are investigated in the context of the integrable Heisenberg model. This type of defects is associated to the (q)-harmonic oscillator algebra. The transmission matrices associated to this particular type of defects are computed via the Bethe ansatz methodology for the XXX model, as well as for the critical and non-critical XXZ spin chain. In the attractive regime of the critical XXZ spin chain the transmission amplitudes for the breathers are also identified.
Type-I integrable quantum impurities in the Heisenberg model
International Nuclear Information System (INIS)
Doikou, Anastasia
2013-01-01
Type-I quantum impurities are investigated in the context of the integrable Heisenberg model. This type of defects is associated to the (q)-harmonic oscillator algebra. The transmission matrices associated to this particular type of defects are computed via the Bethe ansatz methodology for the XXX model, as well as for the critical and non-critical XXZ spin chain. In the attractive regime of the critical XXZ spin chain the transmission amplitudes for the breathers are also identified
Directory of Open Access Journals (Sweden)
Shaoyi Liang
2017-09-01
Full Text Available Closeness measures are crucial to clustering methods. In most traditional clustering methods, the closeness between data points or clusters is measured by the geometric distance alone. These metrics quantify the closeness only based on the concerned data points’ positions in the feature space, and they might cause problems when dealing with clustering tasks having arbitrary clusters shapes and different clusters densities. In this paper, we first propose a novel Closeness Measure between data points based on the Neighborhood Chain (CMNC. Instead of using geometric distances alone, CMNC measures the closeness between data points by quantifying the difficulty for one data point to reach another through a chain of neighbors. Furthermore, based on CMNC, we also propose a clustering ensemble framework that combines CMNC and geometric-distance-based closeness measures together in order to utilize both of their advantages. In this framework, the “bad data points” that are hard to cluster correctly are identified; then different closeness measures are applied to different types of data points to get the unified clustering results. With the fusion of different closeness measures, the framework can get not only better clustering results in complicated clustering tasks, but also higher efficiency.
Retail Services and Pricing Decisions in a Closed-Loop Supply Chain with Remanufacturing
Directory of Open Access Journals (Sweden)
Zhen-Zheng Zhang
2015-02-01
Full Text Available Environmental and social responsibilities have led many manufacturers to used products recovery. Meanwhile, many manufacturers nowadays sell products via indirect retailer channels and direct Internet channels. This paper models a dual-channel closed-loop supply chain to improve the sustainability of products. We apply the two-stage optimization technique and the Nash game to examine the impacts of the retail services and the degree of customer loyalty to the retail channel on the pricing of players in a centralized and a decentralized dual-channel supply chain. Our results show that the retail services have a great impact on the manufacturer and the retailer’s pricing strategies. We also compare the differences of pricing strategies between a centralized and a decentralized dual-channel supply chain and suggest the optimal retail services and pricing decisions for the players in the supply chain.
A Sustainable Closed-Loop Supply Chain Decision Mechanism in the Electronic Sector
Directory of Open Access Journals (Sweden)
Jiafu Su
2018-04-01
Full Text Available In a closed-loop supply chain for electronic products, the manufacturer’s priority is to enhance the residual value of the collected end-of-use product and decide whether to outsource this business to a retailer, a third-party service, or retain it exclusively. In this paper, we constructed three models to study the decision mechanism in a closed-loop supply chain, with different players selected to collect the used product. By comparing the three models, we characterized the conditions under which the manufacturer will benefit most, and we then aimed to determine the best choice for the manufacturer. Our findings show that, when the retailer and the third-party service provider provide equal performance in collecting the used product, the manufacturer will give priority to the third-party service provider if they choose to outsource this business. If the reverse flows managed by the retailer result in a higher payoff for the manufacturer, then the manufacturer will choose to outsource this business to the retailer who will also benefit.
Closed loop supply chain in printing operation
Directory of Open Access Journals (Sweden)
Marcius Fabius Henriques Carvalho
2011-12-01
Full Text Available There is a clear change in focus in large companies, previously dedicated primarily to the production of physical goods, toward offering complimentary services and changing their focus toward more service-oriented businesses, in order to increase their competitiveness. At the same time, companies are facing increasing product returns due to various reasons leading to reverse logistics practices and toward the introduction of a Closed Loop Supply Chain management perspective. The purpose of this work is to identify, using a case study in the printing industry, specific characteristics, regarding product returns, both in a product-oriented and a service-oriented operation. Furthermore, the current work performs a diagnosis of current practices applications of CLSC models in the two operating models. The paper concludes that indeed there are relevant differences in managing the CLSC for each case and identify the main gaps for each operation.
On the τ(2)-model in the chiral Potts model and cyclic representation of the quantum group Uq(sl2)
International Nuclear Information System (INIS)
Roan Shishyr
2009-01-01
We identify the precise relationship between the five-parameter τ (2) -family in the N-state chiral Potts model and XXZ chains with U q (sl 2 )-cyclic representation. By studying the Yang-Baxter relation of the six-vertex model, we discover a one-parameter family of L-operators in terms of the quantum group U q (sl 2 ). When N is odd, the N-state τ (2) -model can be regarded as the XXZ chain of U q (sl 2 ) cyclic representations with q N =1. The symmetry algebra of the τ (2) -model is described by the quantum affine algebra U q (sl 2 -hat) via the canonical representation. In general, for an arbitrary N, we show that the XXZ chain with a U q (sl 2 )-cyclic representation for q 2N = 1 is equivalent to two copies of the same N-state τ (2) -model. (fast track communication)
DEFF Research Database (Denmark)
Soleimani, Hamed; Kannan, Govindan
2015-01-01
Today, tracking the growing interest in closed-loop supply chain shown by both practitioners and academia is easily possible. There are many factors, which transform closed-loop supply chain issues into a unique and vital subject in supply chain management, such as environmental legislation...... is proposed and a complete validation process is undertaken using CPLEX and MATLAB software. In small instances, the global optimum points of CPLEX for the proposed hybrid algorithm are compared to genetic algorithm, and particle swarm optimization. Then, in small, mid, and large-size instances, performances...
Closed-Loop Supply Chain Planning Model of Rare Metals
Directory of Open Access Journals (Sweden)
Dongmin Son
2018-04-01
Full Text Available Rare metals (RMs are becoming increasingly important in high-tech industries associated with the Fourth Industrial Revolution, such as the electric vehicle (EV and 3D printer industries. As the growth of these industries accelerates in the near future, manufacturers will also face greater RM supply risks. For this reason, many countries are putting considerable effort into securing the RM supply. For example, countries including Japan, Korea, and the USA have adopted two major policies: the stockpile system and Extended Producer Responsibility (EPR. Therefore, it is necessary for the manufacturers with RMs to establish a suitable supply chain plan that reflects this situation. In this study, the RM classification matrix is created based on the stockpile and recycling level in Korea. Accordingly, three different types of supply chain are designed in order to develop the closed-loop supply chain (CLSC planning model of RM, and the CLSC planning models of RM are validated through experimental analysis. The results show that the stockpiling and the EPR recycling obligation increase the amount of recycled flow and reduce the total cost of the part manufacturing, which means that these two factors are significant for obtaining sustainability of the RMs’ CLSC. In addition, the government needs to set an appropriate sharing cost for promoting the manufacturer’s recycling. Also, from the manufacturer’s perspective, it is better to increase the return rate by making a contract with the collectors to guarantee the collection of used products.
DEFF Research Database (Denmark)
Østergaard, Lars; Traulsen, J; Birkelund, Svend
1991-01-01
the two test systems were compared, the overall sensitivity of the polymerase chain reaction was 96% and the specificity 94% when compared to the cell culture technique. By use of a closed system for DNA extraction and sample transfer for the polymerase chain reaction, contamination of the samples......Two hundred and fifty-four specimens from males and females consulting a clinic for sexually transmitted diseases were analyzed for genital Chlamydia trachomatis infection. Each clinical sample was tested by the cell culture technique and the polymerase chain reaction using a closed system. When...... not detect Chlamydia trachomatis after sufficient antibiotic treatment of the chlamydial infections....
DEFF Research Database (Denmark)
Østergaard, Lars; Traulsen, J; Birkelund, Svend
1993-01-01
the two test systems were compared, the overall sensitivity of the polymerase chain reaction was 96% and the specificity 94% when compared to the cell culture technique. By use of a closed system for DNA extraction and sample transfer for the polymerase chain reaction, contamination of the samples......Two hundred and fifty-four specimens from males and females consulting a clinic for sexually transmitted diseases were analyzed for genital Chlamydia trachomatis infection. Each clinical sample was tested by the cell culture technique and the polymerase chain reaction using a closed system. When...... not detect Chlamydia trachomatis after sufficient antibiotic treatment of the chlamydial infections....
Evaluation of nuclides with closely spaced values of depletion constants in transmutation chains
International Nuclear Information System (INIS)
Vukadin, Z.S.
1977-01-01
New method of calculating nuclide concentrations in a transmutation chain is developed in this thesis. Method is based on originally derived recurrence formulas for expansion series of depletion functions and on originally obtained, nonsingular, Bateman coefficients. Explicit expression for the nuclide concentrations in a transmutation chain is obtained. This expression can be used as it stands for arbitrary values of nuclides depletion constants. By computing hypothetical transmutation chains and neptunium series, method is compared with the Bateman analytical solution, with the approximate solutions and with the matrix exponential method. It comes out that the method presented in this thesis is suitable for calculating very long depletion chains even in the case of some closely spaced and/or equal values of nuclide depletion constants. Though, presented method is of great practical applicability in a number of nuclear physics problems that are dealing with the nuclide transmutations: starting from the studies of the stellar evolution up to the design of nuclear reactors (author) [sr
Trajectory control of robot manipulators with closed-kinematic chain mechanism
Nguyen, Charles C.; Pooran, Farhad J.; Premack, Timothy
1987-01-01
The problem of Cartesian trajectory control of a closed-kinematic chain mechanism robot manipulator, recently built at CAIR to study the assembly of NASA hardware for the future Space Station, is considered. The study is performed by both computer simulation and experimentation for tracking of three different paths: a straight line, a sinusoid, and a circle. Linearization and pole placement methods are employed to design controller gains. Results show that the controllers are robust and there are good agreements between simulation and experimentation. The results also show excellent tracking quality and small overshoots.
Incorporating risk measures in closed-loop supply chain network design
DEFF Research Database (Denmark)
Soleimani, H.; Seyyed-Esfahani, M.; Govindan, Kannan
2014-01-01
This paper considers a location-allocation problem in a closed-loop supply chain (CLSC) with two extensions: first, demand and prices of new and return products are regarded as non-deterministic parameters and second, the objective function is developed from expected profit to three types of mean......-risk ones. Indeed, design and planning an integrated CLSC in real-world volatile markets is an important and necessary issue. Further, risk-neutral approaches, which are considered expected values, are not efficient for such uncertain conditions. Hence, this paper, copes with the design and planning problem...
Directory of Open Access Journals (Sweden)
Zunya Shi
2016-01-01
Full Text Available The importance of remanufacturing has been recognized in research and practice. The integrated system, combining the forward and reverse activities of supply chains, is called closed-loop supply chain (CLSC system. By coordination in the CLSC system, players will get economic improvement. This paper studies different coordination performances of two types of contracts, two-part tariff (TTC and reverse revenue sharing contract (RRSC, in a closed-loop system. Through mathematical analysis based on Stackelberg Game Theory, we find that it is easy for manufacturer to improve more profits and retailer’s collection effects by adjusting the ratio of transfer collection price through RRSC, and we also give the function to calculate the best ratio of transfer collection price, which may be a valuable reference for the decision maker in practice. Besides, our results also suggest that although the profits of the coordinated CLSC system are always higher than the contradictory scenario, the RRSC is more favorable to the manufacturer than to the retailer, as results show that the manufacturer will share more profits from the system through RRSC. Therefore, RRSC has attracted the manufacturers more to closing the supply chain for economic consideration.
Inventory decision in a closed-loop supply chain with inspection, sorting, and waste disposal
Dwicahyani, A. R.; Jauhari, W. A.; Kurdhi, N. A.
2016-02-01
The study of returned item inventory management in a closed-loop supply chain system has become an important issue in recent years. So far, investigations about inventory decision making in a closed-loop supply chain system have been confined to traditional forward and reverse oriented material flow supply chain. In this study, we propose an integrated inventory model consisting a supplier, a manufacturer, and a retailer where the manufacturer inspects all of the returned items collected from the customers and classifies them as recoverable or waste. Returned items that recovered through the remanufacturing process and the newly manufactured products are then used to meet the demand of the retailer. However, some recovered items which are not comparable to the ones in quality, classified as refurbished items, are sold to a secondary market at a reduced price. This study also suggests that the flow of returned items is controlled by a decision variable, namely an acceptance quality level of recoverable item in the system. We apply multiple remanufacturing cycle and multiple production cycle policy to the proposed model and give the corresponding iterative procedure to determine the optimal solutions. Further, numerical examples are presented for illustrative purpose.
Zhu, Xiaodong; Wang, Jing; Tang, Juan
2017-12-15
Environmentally friendly handling and efficient recycling of waste electrical on Waste Electrical and Electronic Equipment (WEEE) have grown to be a global social problem. As holders of WEEE, consumers have a significant effect on the recycling process. A consideration of and attention to the influence of consumer behavior in the recycling process can help achieve more effective recycling of WEEE. In this paper, we built a dual-channel closed-loop supply chain model composed of manufacturers, retailers, and network recycling platforms. Based on the influence of customer bargaining behavior, we studied several different scenarios of centralized decision-making, decentralized decision-making, and contract coordination, using the Stackelberg game theory. The results show that retailers and network recycling platforms will reduce the direct recovery prices to maintain their own profit when considering the impact of consumer bargaining behavior, while remanufacturers will improve the transfer payment price for surrendering part of the profit under revenue and the expense sharing contract. Using this contract, we can achieve supply chain coordination and eliminate the effect of consumer bargaining behavior on supply chain performance. It can be viewed from the parameter sensitivity analysis that when we select the appropriate sharing coefficient, the closed-loop supply chain can achieve the same system performance under a centralized decision.
Directory of Open Access Journals (Sweden)
Xiaodong Zhu
2017-12-01
Full Text Available Environmentally friendly handling and efficient recycling of waste electrical on Waste Electrical and Electronic Equipment (WEEE have grown to be a global social problem. As holders of WEEE, consumers have a significant effect on the recycling process. A consideration of and attention to the influence of consumer behavior in the recycling process can help achieve more effective recycling of WEEE. In this paper, we built a dual-channel closed-loop supply chain model composed of manufacturers, retailers, and network recycling platforms. Based on the influence of customer bargaining behavior, we studied several different scenarios of centralized decision-making, decentralized decision-making, and contract coordination, using the Stackelberg game theory. The results show that retailers and network recycling platforms will reduce the direct recovery prices to maintain their own profit when considering the impact of consumer bargaining behavior, while remanufacturers will improve the transfer payment price for surrendering part of the profit under revenue and the expense sharing contract. Using this contract, we can achieve supply chain coordination and eliminate the effect of consumer bargaining behavior on supply chain performance. It can be viewed from the parameter sensitivity analysis that when we select the appropriate sharing coefficient, the closed-loop supply chain can achieve the same system performance under a centralized decision.
Zhu, Xiaodong; Wang, Jing; Tang, Juan
2017-01-01
Environmentally friendly handling and efficient recycling of waste electrical on Waste Electrical and Electronic Equipment (WEEE) have grown to be a global social problem. As holders of WEEE, consumers have a significant effect on the recycling process. A consideration of and attention to the influence of consumer behavior in the recycling process can help achieve more effective recycling of WEEE. In this paper, we built a dual-channel closed-loop supply chain model composed of manufacturers, retailers, and network recycling platforms. Based on the influence of customer bargaining behavior, we studied several different scenarios of centralized decision-making, decentralized decision-making, and contract coordination, using the Stackelberg game theory. The results show that retailers and network recycling platforms will reduce the direct recovery prices to maintain their own profit when considering the impact of consumer bargaining behavior, while remanufacturers will improve the transfer payment price for surrendering part of the profit under revenue and the expense sharing contract. Using this contract, we can achieve supply chain coordination and eliminate the effect of consumer bargaining behavior on supply chain performance. It can be viewed from the parameter sensitivity analysis that when we select the appropriate sharing coefficient, the closed-loop supply chain can achieve the same system performance under a centralized decision. PMID:29244778
Directory of Open Access Journals (Sweden)
Gitanjali Nandkumar Rangole
2015-12-01
Full Text Available Background: Patello femoral pain syndrome is dull, aching pain anterior to knee which frequently activity related may be present in one or both knees with difficulty in walking, running. The purpose of the study is to evaluate the effect of open kinetic chain exercise with Kinesio taping versus close kinetic chain exercise with kinesio taping for improving pain and functional mobility in subjects with unilateral patellofemoral pain syndrome. Methods: An Experimental study design, 30 subjects with unilateral patellofemoral pain were selected and randomized 15 subjects into each two groups. Group-A received Open Kinetic chain exercise with Kinesio taping while Group-B received Close kinetic chain exercises with kinesio taping. The duration of intervention was 2 weeks. Outcome measure such as Functional mobility was measured using a Kujala questionnaire and pain was measured using a VAS scale before and after two weeks of intervention. Results: Analysis using Independent ‘t’ test and Mann Whitney U test found that there is statistically significant difference with p<0.000 when pre to post interventions means were compared within the groups. When post intervention means between the Group-A and Group-B were compared there is a significant statistical difference in VAS and functional mobility. Conclusion: The present study concluded that both Open kinetic chain exercise with kinesio taping and close kinetic chain exercise with kinesio taping are effective in improving functional mobility and Pain. However close kinetic chain exercises with Kinesio taping shown greater percentage of effect in improving pain and functional mobility than open kinetic chain exercise.
A Study of the Closed-Loop Supply Chain Coordination on Waste Glass Bottles Recycling
Directory of Open Access Journals (Sweden)
Wenxue Ran
2016-01-01
Full Text Available The recycling of waste products can sharply save manufacturing cost and improve the economic efficiency and corporate-reputation. It also has a great effect on the environment and resources protection. In the management of the closed-loop supply chain, the recycling of waste products and decision-making on pricing often directly affect the supply and demand of products and the operation efficiency of supply chain. Therefore, first we take waste glass bottles as an example and establish a mathematical model to solve the profit of manufacturers and retailers solely. Then, we analyzed whole supply chain profit under a dual-channel recycling condition which is directly recycled by consumers or by retailers. Finally, we concluded that no matter what product’s price, quality, profit, or operational efficiency of supply chain is, the overall recycling is better than the single node recycling model. Based on the analysis, we developed a new model to coordinate the profit of manufacturers and retailers in the supply chain with revenue-sharing contract. A numerical study shows that this approach is applicable and effective.
Design of Closed Loop Supply Chains
H.R. Krikke (Harold); J.M. Bloemhof-Ruwaard (Jacqueline); L.N. van Wassenhove (Luk)
2001-01-01
textabstractIncreased concern for the environment has lead to new techniques to design products and supply chains that are both economically and ecologically feasible. This paper deals with the product - and corresponding supply chain design for a refrigerator. Literature study shows that there are
Directory of Open Access Journals (Sweden)
Guitao Zhang
2014-01-01
Full Text Available This paper studies a closed-loop supply chain network equilibrium problem in multiperiod planning horizons with consideration of product lifetime and carbon emission constraints. The closed-loop supply chain network consists of suppliers tier, manufacturer tier, retailers tier, and demand markets tier, in which the manufacturers collect used products from the demand markets directly. Product lifetime is introduced to denote the maximum times of manufacturing and remanufacturing, and the relation between adjacent periods is described by inventory transfer. By variational inequalities and complementary theory, the optimal behaviors of all the players are modeled, and, in turn, the governing closed-loop supply chain network equilibrium model is established. The model is solved by modified project contraction algorithm with fixed step. Optimal equilibrium results are computed and analyzed through numerical examples. The impacts of collection rate, remanufacturing conversion rate, product lifetime, and carbon emission cap on equilibrium states are analyzed. Finally, several managerial insights are given to provide decision support for entrepreneurs and government official along with some inspirations for future research.
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Zahra Firoozkoohi Moghadam
2016-11-01
Full Text Available Introduction: Patellofemoral pain syndrome is one of the most prevalent problems in physically active people. The syndrome is a multifactorial disorder with different therapeutic approaches. Conservative treatment of the syndrome has been a crucial matter in different studies. Quadriceps muscle strengthening exercise is a recommended approach which is performed in forms of open and closed kinetic chain exercises. This study was designed to compare the efficacy of these exercises on this syndrome. Methods: Totally 30 women suffering from the syndrome aged 30-40 were randomly allocated into three groups: open, and closed kinetic chain exercises, and control group, as groups A, B, and C, respectively. Groups A and B participated in 28 sessions of exercises in a period of four weeks and group C did not do any exercise in this period. Before and after the period, pain and function of the participants were assessed using visual analog scale (VAS and Kujala patellofemoral scale, respectively. Data were analyzed using independent t test, dependent t test, and univariate variance analysis, while significance of data was determined at P < 0.05. Results: The study indicated that open kinetic chain exercises (group A for 4 weeks brought significant changes in relieving the pain along with improving the function (P = 0.001. Likewise, it was revealed a significant pain relief as well as function improvement in group B (P = 0.001. Comparing two groups illustrated that benefits of open kinetic chain exercises outweigh closed ones (P = 0.001. Conclusion: Overall, both exercises were efficient in relieving pain as well as improving function, however open kinetic chain exercises were more contributory.
Static and Dynamic Pricing Strategies in a Closed-Loop Supply Chain with Reference Quality Effects
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Zhichao Zhang
2018-01-01
Full Text Available Remanufacturing of returned products has been increasingly recognized in industries as an effective approach to face environmental responsibility, government regulations, and increased awareness of consumers. In this paper, we address a closed-loop supply chain (CLSC in which the manufacturer produces the brand-new products, as well as the remanufactured goods while the retailer sells these products to customers. We consider several different scenarios: the manufacturer and the retailer adopt a steady-state price or a dynamic price with reference quality effects in a centralized case; either, neither or both the manufacturer and the retailer price dynamically with reference quality effects, respectively, in a decentralized model. We solve the problem with the retailer recycling the sold copies and deduce the optimal pricing strategies while the manufacturer in charge of recovering the used items in such a CLSC. The result shows that dynamic pricing strategies are much more profitable for the supply chain and its members when compared with pricing statically; the dynamic pricing strategies with time-varying quality characterized by reference quality are more suited to a long-term and cooperative closed-loop supply chain. Moreover, the optimal recycling fraction relies on the recovery cost coefficient and proves to be uniform despite adopting a dynamic price and quality in all distinct cases.
Zaletel, Michael P; Bardarson, Jens H; Moore, Joel E
2011-07-08
Universal logarithmic terms in the entanglement entropy appear at quantum critical points (QCPs) in one dimension (1D) and have been predicted in 2D at QCPs described by 2D conformal field theories. The entanglement entropy in a strip geometry at such QCPs can be obtained via the "Shannon entropy" of a 1D spin chain with open boundary conditions. The Shannon entropy of the XXZ chain is found to have a logarithmic term that implies, for the QCP of the square-lattice quantum dimer model, a logarithm with universal coefficient ±0.25. However, the logarithm in the Shannon entropy of the transverse-field Ising model, which corresponds to entanglement in the 2D Ising conformal QCP, is found to have a singular dependence on the replica or Rényi index resulting from flows to different boundary conditions at the entanglement cut.
An Experimental Research on Closed Loop Supply Chain Management with Internet of Things
PAKSOY, Turan; KARAOĞLAN, İsmail; GÖKÇEN, Hadi; PARDALOS, Panos M.; TORĞUL, Belkıs
2016-01-01
Abstract. Closed loop supply chain (CLSC) optimization is integration of forward and reverse logistics activities. The importance of CLSC management is increasing by legal regulations, limited energy resources and environmental- financial problems that growing in recent years. However, reverse logistics part of the CLSC is a flow type which is more difficult to made predictions, planning and controls by reason contained uncertainties. This stage, Internet of Things system reduces related unce...
De Luca, Andrea; Collura, Mario; De Nardis, Jacopo
2017-07-01
We construct exact steady states of unitary nonequilibrium time evolution in the gapless XXZ spin-1/2 chain where integrability preserves ballistic spin transport at long times. We characterize the quasilocal conserved quantities responsible for this feature and introduce a computationally effective way to evaluate their expectation values on generic matrix product initial states. We employ this approach to reproduce the long-time limit of local observables in all quantum quenches which explicitly break particle-hole or time-reversal symmetry. We focus on a class of initial states supporting persistent spin currents and our predictions remarkably agree with numerical simulations at long times. Furthermore, we propose a protocol for this model where interactions, even when antiferromagnetic, are responsible for the unbounded growth of a macroscopic magnetic domain.
Introduction to integrable many-body systems II
International Nuclear Information System (INIS)
Samaj, L.
2010-01-01
This is the second part of a three-volume introductory course about integrable systems of interacting bodies. The models of interest are quantum spin chains with nearest-neighbor interactions between spin operators, in particular Heisenberg spin- 2 models. The Ising model in a transverse field, expressible as a quadratic fermion form by using the Jordan-Wigner transformation, is the subject of Sect. 12. The derivation of the coordinate Bethe ansatz for the XXZ Heisenberg chain and the determination of its absolute ground state in various regions of the anisotropy parameter are presented in Sect. 13. The magnetic properties of the ground state are explained in Sect. 14. Sect. 15 concerns excited states and the zero-temperature thermodynamics of the XXZ model. The thermodynamics of the XXZ Heisenberg chain is derived on the basis of the string hypothesis in Sect. 16; the thermodynamic Bethe ansatz equations are analyzed in high-temperature and low-temperature limits. An alternative derivation of the thermodynamics without using strings, leading to a non-linear integral equation determining the free energy, is the subject of Sect. 17. A nontrivial application of the Quantum Inverse Scattering method to the fully anisotropic XYZ Heisenberg chain is described in Section 18. Section 19 deals with integrable cases of isotropic spin chains with an arbitrary spin. (Author)
Profit Analysis and Supply Chain Planning Model for Closed-Loop Supply Chain in Fashion Industry
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Jisoo Oh
2014-12-01
Full Text Available In recent decades, due to market growth and use of synthetic fiber, the fashion industry faces a rapid increase of CO2 emission throughout the production cycle and raises environmental issues in recovery processing. This study proposes a closed-loop supply chain (CLSC structure in fashion industry and develops its planning model as multi-objective mixed integer linear programming to find an optimal trade-off between CLSC profit and CO2 emission. The planning model is associated with the profit analysis of each member in CLSC to find the optimal price of products on CLSC network. The model determines optimal production, transportation, and inventory quantities on CLSC network. The proposed models are validated using numerical experiments and sensitivity analyses, and from the results some managerial insights are addressed.
Groundstate fidelity phase diagram of the fully anisotropic two-leg spin-½ XXZ ladder
Li, Sheng-Hao; Shi, Qian-Qian; Batchelor, Murray T.; Zhou, Huan-Qiang
2017-11-01
The fully anisotropic two-leg spin-\\tfrac{1}{2} XXZ ladder model is studied in terms of an algorithm based on the tensor network (TN) representation of quantum many-body states as an adaptation of projected entangled pair states to the geometry of translationally invariant infinite-size quantum spin ladders. The TN algorithm provides an effective method to generate the groundstate wave function, which allows computation of the groundstate fidelity per lattice site, a universal marker to detect phase transitions in quantum many-body systems. The groundstate fidelity is used in conjunction with local order and string order parameters to systematically map out the groundstate phase diagram of the ladder model. The phase diagram exhibits a rich diversity of quantum phases. These are the ferromagnetic, stripe ferromagnetic, rung singlet, rung triplet, Néel, stripe Néel and Haldane phases, along with the two XY phases XY1 and XY2.
Qingming Zou; Guangyu Ye
2015-01-01
In a closed-loop supply chain consisting of a manufacturer and a retailer, this paper studies the pricing strategies and coordination mechanism of supply chain when the remanufacturing cost is random caused by the proportion of reusability parts in design stage and quality condition of recycling product. The results show that the wholesale price and retail price are negative correlation, while the recycling rate and total profit of supply chain system are positive correlation with the proport...
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Indri Susilawati
2015-01-01
Full Text Available Knee osteoarthritis is a disease caused by degenerative factors that mostly found in musculoskeletal and knee osteoarthritis has the most common cause to limited motion and body function. People with osteoarthritis usually complain of pain, stifftess and limitation of function. This study aimed to determine closed kinetic chain exercise was better than open kinetic chain to increase functional capability of knee osteoarthritis after giving treatment micro wave diathermy (MWD and transcutaneus electrical nerve stimulation (TENS. The design of this research was true experimental pre-test and post-test with control group design, which the population was taken by purposively sampling. Division of the sample into two groups, group one consisted of 6 people. The first group was given MWD, TENS and Closed Kinetic Chain exercise and group two was given MWD, TENS and Open Kinetic Chain exercise. The frequency of exercise are 3 times a week for 4 weeks. Subjects were all patients with knee osteoarthritis who had been diagnosed through assesment procedures conducted in General Hospital of Mataram–Lombok, West Nusa Tenggara. Analysis of significance with Paired t-test (paired showed that in each group resulted in an increase in functional ability after treatment of knee osteoarthritis is significantly different (p<0.05. While a difference test in both groups after treatment using analysis test of Independent t-test (unpaired showed that the value of t = 2.748 and p = 0.021. So thah there was an increase functional capabilities of knee osteoarthritis after treatment (p<0.05. In conclution the treatment conducted in group one which was MWD, TENS and Closed Kinetic Chain proved improvement of the functional capabilities of knee osteoarthritis better than treatment conducted in group two, namely the MWD, TENS and Open Kinetic Chain.
Correlation functions of the spin chains. Algebraic Bethe Ansatz approach
International Nuclear Information System (INIS)
Kitanine, N.
2007-09-01
Spin chains are the basic elements of integrable quantum models. These models have direct applications in condense matter theory, in statistical physics, in quantum optics, in field theory and even in string theory but they are also important because they enable us to solve, in an exact manner, non-perturbative phenomena that otherwise would stay unresolved. The method described in this work is based on the algebraic Bethe Ansatz. It is shown how this method can be used for the computation of null temperature correlation functions of the Heisenberg 1/2 spin chain. The important point of this approach is the solution of the inverse quantum problem given by the XXZ spin chain. This solution as well as a simple formulae for the scalar product of the Bethe states, have enabled us to get the most basic correlation functions under the form of multiple integrals. The formalism of multiple integrals open the way for asymptotic analysis for a few physical quantities like the probability of vacuum formation. It is worth noticing that this formalism can give exact results for two-point functions that are the most important correlation functions for applications. A relationship has been discovered between these multiple integrals and the sum of the form factors. The results have been extended to dynamical correlation functions. (A.C.)
Energy Technology Data Exchange (ETDEWEB)
Kitanine, N
2007-09-15
Spin chains are the basic elements of integrable quantum models. These models have direct applications in condense matter theory, in statistical physics, in quantum optics, in field theory and even in string theory but they are also important because they enable us to solve, in an exact manner, non-perturbative phenomena that otherwise would stay unresolved. The method described in this work is based on the algebraic Bethe Ansatz. It is shown how this method can be used for the computation of null temperature correlation functions of the Heisenberg 1/2 spin chain. The important point of this approach is the solution of the inverse quantum problem given by the XXZ spin chain. This solution as well as a simple formulae for the scalar product of the Bethe states, have enabled us to get the most basic correlation functions under the form of multiple integrals. The formalism of multiple integrals open the way for asymptotic analysis for a few physical quantities like the probability of vacuum formation. It is worth noticing that this formalism can give exact results for two-point functions that are the most important correlation functions for applications. A relationship has been discovered between these multiple integrals and the sum of the form factors. The results have been extended to dynamical correlation functions. (A.C.)
Zhang, Ren-jie; Xu, Shuai; Shi, Jia-dong; Ma, Wen-chao; Ye, Liu
2015-11-01
In the paper, we researched the quantum phase transition (QPT) in the anisotropic spin XXZ model by exploiting the quantum renormalization group (QRG) method. The innovation point is that we adopt a new approach called trace distance discord to indicate the quantum correlation of the system. QPT after several iterations of renormalization in current system has been observed. Consequently, it opened the possibility of investigation of QPR in the geometric discord territory. While the anisotropy suppresses the correlation due to favoring of the alignment of spins, the DM interaction restores the spoiled correlation via creation of the quantum fluctuations. We also apply quantum renormalization group method to probe the thermodynamic limit of the model and emerging of nonanalytic behavior of the correlation.
Optimal Control for Fast and Robust Generation of Entangled States in Anisotropic Heisenberg Chains
Zhang, Xiong-Peng; Shao, Bin; Zou, Jian
2017-05-01
Motivated by some recent results of the optimal control (OC) theory, we study anisotropic XXZ Heisenberg spin-1/2 chains with control fields acting on a single spin, with the aim of exploring how maximally entangled state can be prepared. To achieve the goal, we use a numerical optimization algorithm (e.g., the Krotov algorithm, which was shown to be capable of reaching the quantum speed limit) to search an optimal set of control parameters, and then obtain OC pulses corresponding to the target fidelity. We find that the minimum time for implementing our target state depending on the anisotropy parameter Δ of the model. Finally, we analyze the robustness of the obtained results for the optimal fidelities and the effectiveness of the Krotov method under some realistic conditions.
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Jiajia Nie
2013-01-01
Full Text Available We develop three closed-loop supply chain models where manufacturers can utilize financial or physical support to push a third party to collect the used fashion product for remanufacturing. We first examine two strategies for the collective recycling responsibility (CRR, namely, the financial sharing (FS and the physical sharing (PS, using the model with no CRR as a benchmark. After that, we conduct a detailed comparison among the three models in terms of the retail price, demand, return rate, and the profits received by the supply chain members. With this study, we find the following. (i The FS or PS support offered by the manufacturer to the third party will result in a lower retail price and a higher demand. (ii The optimal return rate with PS scheme is always higher than that without the CRR, and the one with FS scheme is at least as high as that without the CRR. (iii All the members in the closed-loop supply chain can always benefit from the CRR. In addition, (iv which scheme of the FS, PS, or no CRR is the best for the supply chain members will depend heavily on the transfer price of the used product.
Quench action approach for releasing the Néel state into the spin-1/2 XXZ chain
Brockmann, M.; Wouters, B.; Fioretto, D.; De Nardis, J.; Vlijm, R.; Caux, J.-S.
2014-01-01
The steady state after a quantum quench from the Néel state to the anisotropic Heisenberg model for spin chains is investigated. Two methods that aim to describe the postquench non-thermal equilibrium, the generalized Gibbs ensemble and the quench action approach, are discussed and contrasted. Using
Fuzzy multi-objective sustainable and green closed-loop supply chain network design
DEFF Research Database (Denmark)
Soleimani, Hamed; Govindan, Kannan; Saghafi, Hamid
2017-01-01
recycling raw material recycling. Modeling this chain is carried out by accounting for environmental considerations, total profit optimization, and reduction of lost working days due to occupational accidents, we well as maximizing responsiveness to customer demand. In order to solve the model, genetic...... algorithm has been used and multiple scenarios with different aspects have been studied. Solving this model provides decisions regarding opening or closing of each of the components of the network and the optimal product flow among them. The results prove the feasibility of the presented model...... and the applicability of the developed solution methodology....
A Comprehensive Approach in Assessing the Performance of an Automobile Closed-Loop Supply Chain
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Ezutah Udoncy Olugu
2010-03-01
Full Text Available The ecological issues arising from manufacturing operations have led to the focus on environmental sustainability in manufacturing. This can be addressed adequately using a closed-loop supply chain (CLSC. To attain an effective and efficient CLSC, it is necessary to imbibe a holistic performance measurement approach. In order to achieve this, there is a need to adopt a specific approach for a particular product rather than being generic. Since sustainability has direct environmental footprints that involve organizational stakeholders, suppliers, customers and the society at large, complexities surrounding supply chain performance measurement have multiplied. In this study, a suitable approach has been proposed for CLSC performance measurement in the automotive industry, based on reviewed literature. It is believed that this approach will result in increased effectiveness and efficiency in CLSC performance measurement.
Arian Zad, Hamid; Ananikian, Nerses
2017-11-01
We consider a symmetric spin-1/2 Ising-XXZ double sawtooth spin ladder obtained from distorting a spin chain, with the XXZ interaction between the interstitial Heisenberg dimers (which are connected to the spins based on the legs via an Ising-type interaction), the Ising coupling between nearest-neighbor spins of the legs and rungs spins, respectively, and additional cyclic four-spin exchange (ring exchange) in the square plaquette of each block. The presented analysis supplemented by results of the exact solution of the model with infinite periodic boundary implies a rich ground state phase diagram. As well as the quantum phase transitions, the characteristics of some of the thermodynamic parameters such as heat capacity, magnetization and magnetic susceptibility are investigated. We prove here that among the considered thermodynamic and thermal parameters, solely heat capacity is sensitive versus the changes of the cyclic four-spin exchange interaction. By using the heat capacity function, we obtain a singularity relation between the cyclic four-spin exchange interaction and the exchange coupling between pair spins on each rung of the spin ladder. All thermal and thermodynamic quantities under consideration should be investigated by regarding those points which satisfy the singularity relation. The thermal entanglement within the Heisenberg spin dimers is investigated by using the concurrence, which is calculated from a relevant reduced density operator in the thermodynamic limit.
Singha Roy, Sudipto; Dhar, Himadri Shekhar; Rakshit, Debraj; Sen(De), Aditi; Sen, Ujjwal
2017-12-01
Phase transition in quantum many-body systems inevitably causes changes in certain physical properties which then serve as potential indicators of critical phenomena. Besides the traditional order parameters, characterization of quantum entanglement has proven to be a computationally efficient and successful method for detection of phase boundaries, especially in one-dimensional models. Here we determine the rich phase diagram of the ground states of a quantum spin-1/2 XXZ ladder by analyzing the variation of bipartite and multipartite entanglements. Our study characterizes the different ground state phases and notes the correspondence with known results, while highlighting the finer details that emerge from the behavior of ground state entanglement. Analysis of entanglement in the ground state provides a clearer picture of the complex ground state phase diagram of the system using only a moderate-size model.
Wang, Y.; Wiegerinck, V.J.J.; Krikke, H.R.; Zhang, H.
2013-01-01
Purpose – The paper aims to explore the reasons underlying the key assumption in the closed-loop supply chain (CLSC) literature that consumers' purchase intention is lower for remanufactured products than for new products. It aims to complement the predominantly operation-focused CLSC research by
Product recovery optimization in closed-loop supply chain to improve sustainability in manufacturing
DEFF Research Database (Denmark)
Govindan, Kannan; Jha, P. C.; Garg, Kiran
2016-01-01
that emerge from that business’s economical, environmental and social dimensions. In this paper, we propose a multi-objective mixed integer mathematical problem for a generic closed-loop supply chain (CLSC) network to rationalise how a system’s product recovery helps to improve manufacturing sustainability....... The CLSC network proposed in this study consists of a hybrid manufacturing facility, warehouse, distribution centres, collection centres and a hybrid recovery facility (HRF). The proposed model determines the best location for the HRF and optimal flow of products, recovered parts and material...
International Nuclear Information System (INIS)
Patel, Umang R.; Joshipura, K. N.; Pandya, Siddharth H.; Kothari, Harshit N.
2014-01-01
In this paper, we report theoretical electron impact ionization cross sections from threshold to 2000 eV for isocarbonic open chain molecules C 4 H 6 , C 4 H 8 , C 4 F 6 including their isomers, and closed chain molecules c-C 4 H 8 and c-C 4 F 8 . Theoretical formalism employed presently, viz., Complex Scattering Potential-ionization contribution method has been used successfully for a variety of polyatomic molecules. The present ionization calculations are very important since results available for the studied targets are either scarce or none. Our work affords comparison of C 4 containing hydrocarbon versus fluorocarbon molecules. Comparisons of the present ionization cross sections are made wherever possible, and new ionization data are also presented
International Nuclear Information System (INIS)
Song, Xue-ke; Wu, Tao; Xu, Shuai; He, Juan; Ye, Liu
2014-01-01
In this paper, we have investigated the dynamical behaviors of the two important quantum correlation witnesses, i.e. geometric quantum discord (GQD) and Bell–CHSH inequality in the XXZ model with DM interaction by employing the quantum renormalization group (QRG) method. The results have shown that the anisotropy suppresses the quantum correlations while the DM interaction can enhance them. Meanwhile, using the QRG method we have studied the quantum phase transition of GQD and obtained two saturated values, which are associated with two different phases: spin-fluid phase and the Néel phase. It is worth mentioning that the block–block correlation is not strong enough to violate the Bell–CHSH inequality in the whole iteration steps. Moreover, the nonanalytic phenomenon and scaling behavior of Bell inequality are discussed in detail. As a byproduct, the conjecture that the exact lower and upper bounds of Bell inequality versus GQD can always be established for this spin system although the given density matrix is a general X state
Directory of Open Access Journals (Sweden)
Junhai Ma
2014-01-01
Full Text Available This paper studied some realistic recycle fields at present in China, such as some daily machinery and equipment, electronic products, and plastic products. Under such circumstance, three oligarch retailers are a common situation. In this paper, we model and analyze the game of three oligarch retailers in a closed-loop supply chain. The stability of the Nash equilibrium, the bifurcation and chaos phenomenon of the recycling price and new product quantity when retailers change its adjustment speed, the profit trends of the three retailers, and the power spectrum are studied. At last, we used the parameter adjustment and the variable state feedback control strategy for chaos control, and the chaos of the system is delayed effectively. For closed-loop supply chain research, the conclusions of the numerical simulation in this paper not only have realistic guiding significance, but also have theoretical reference value.
Schroeter, Marcus; Spengler, Thomas
2004-02-01
The strategy to recover components from discarded electrical and electronic equipment to obtain spare parts is promising, especially during the final service phase. In that phase, the original product is no longer produced and the sources of new parts are often limited. Controlling those closed-loop supply chains is challenging. Decision makers have to choose when to acquire discarded equipment, when to recover used parts, and when to produce new parts. We developed a generic system dynamics model that provides a test for various proposed policies to control closed-loop supply chains with parts recovery and spare-parts supply.
Quantum chaos in the Heisenberg spin chain: The effect of Dzyaloshinskii-Moriya interaction.
Vahedi, J; Ashouri, A; Mahdavifar, S
2016-10-01
Using one-dimensional spin-1/2 systems as prototypes of quantum many-body systems, we study the emergence of quantum chaos. The main purpose of this work is to answer the following question: how the spin-orbit interaction, as a pure quantum interaction, may lead to the onset of quantum chaos? We consider the three integrable spin-1/2 systems: the Ising, the XX, and the XXZ limits and analyze whether quantum chaos develops or not after the addition of the Dzyaloshinskii-Moriya interaction. We find that depending on the strength of the anisotropy parameter, the answer is positive for the XXZ and Ising models, whereas no such evidence is observed for the XX model. We also discuss the relationship between quantum chaos and thermalization.
2013-01-01
The concepts of Quality Management (QM) have been used for a long time by manufacturing companies to ensure customers receive a constant and high quality level of products. But what happens with remanufactured or refurbished products? Quality Management in Reverse Logistics: A Broad Look on Quality Issues and Their Interaction with Closed-Loop Supply Chains discusses the new, promising area of QM and Reverse Logistics interaction. More specifically, it examines and evaluates a number of QM tools and techniques, which can be applied in practice in order to understand, review and improve any closed-loop supply chain process. Modeling and quantitative methods that can be used by students, practitioners and academics in the Reverse Logistics industry are described. The readers will broaden their scope of thinking in the area of Reverse Logistics, where Quality Management can be applied.
Using the J1–J2 quantum spin chain as an adiabatic quantum data bus
International Nuclear Information System (INIS)
Chancellor, Nicholas; Haas, Stephan
2012-01-01
This paper investigates numerically a phenomenon which can be used to transport a single q-bit down a J 1 –J 2 Heisenberg spin chain using a quantum adiabatic process. The motivation for investigating such processes comes from the idea that this method of transport could potentially be used as a means of sending data to various parts of a quantum computer made of artificial spins, and that this method could take advantage of the easily prepared ground state at the so-called Majumdar–Ghosh point. We examine several annealing protocols for this process and find similar results for all of them. The annealing process works well up to a critical frustration threshold. There is also a brief section examining what other models this protocol could be used for, examining its use in the XXZ and XYZ models. (paper)
DEFF Research Database (Denmark)
Wei, Jie; Govindan, Kannan; Li, Yongjian
2015-01-01
. The optimal strategies in closed form are given under the decision scenarios with symmetric information; moreover, the first order conditions that the optimal retail price, optimal wholesale price, and optimal collection rate satisfy are given under the decision scenarios with asymmetric information......The optimal decision problem of a closed-loop supply chain with symmetric and asymmetric information structures is considered using game theory in this paper. The paper aims to explore how the manufacturer and the retailer make their own decisions about wholesale price, retail price, and collection...... rate under symmetric and asymmetric information conditions. Four game models are established, which allow one to examine the strategies of each firm and explore the role of the manufacturer and the retailer in four different game scenarios under symmetric and asymmetric information structures...
Directory of Open Access Journals (Sweden)
Min Huang
2017-12-01
Full Text Available Firms engaged in remanufacturing activities generally adopt more than one recycling channel to collect more used products and gain more profits. This paper explores the optimal strategies for a retailer-dominated closed-loop supply chain (CLSC with a triple recycling channel in the construction machinery remanufacturing context. In this special system, the retailer is the leader and authorized by the original equipment manufacturer (OEM to remanufacture. Moreover, the OEM, the retailer, and the secondary market all take part in the used products collection activities. Considering the differentiation of the OEM, the retailer, and the secondary market in collecting the used construction machinery, a mathematical model of the CLSC system based on reasonable assumptions is built, the closed-form optimal pricing decisions are derived, and the optimal collection efforts allocation strategies are explored within the framework of the game theory. In addition, the impacts of the reverse logistics cost coefficient, the competing coefficient, and the buy-back price coefficient on the supply chain performance are elaborately analyzed. These achievements provide decision makers with managerial insights and offer efficient guidelines for the construction machinery remanufacturing firms to solve similar puzzles.
Entanglement in correlated random spin chains, RNA folding and kinetic roughening
International Nuclear Information System (INIS)
Rodríguez-Laguna, Javier; Santalla, Silvia N; Ramírez, Giovanni; Sierra, Germán
2016-01-01
Average block entanglement in the 1D XX-model with uncorrelated random couplings is known to grow as the logarithm of the block size, in similarity to conformal systems. In this work we study random spin chains whose couplings present long range correlations, generated as gaussian fields with a power-law spectral function. Ground states are always planar valence bond states, and their statistical ensembles are characterized in terms of their block entropy and their bond-length distribution, which follow power-laws. We conjecture the existence of a critical value for the spectral exponent, below which the system behavior is identical to the case of uncorrelated couplings. Above that critical value, the entanglement entropy violates the area law and grows as a power law of the block size, with an exponent which increases from zero to one. Interestingly, we show that XXZ models with positive anisotropy present the opposite behavior, and strong correlations in the couplings lead to lower entropies. Similar planar bond structures are also found in statistical models of RNA folding and kinetic roughening, and we trace an analogy between them and quantum valence bond states. Using an inverse renormalization procedure we determine the optimal spin-chain couplings which give rise to a given planar bond structure, and study the statistical properties of the couplings whose bond structures mimic those found in RNA folding. (paper)
Optimal inventory policy in a closed loop supply chain system with multiple periods
International Nuclear Information System (INIS)
Sasi Kumar, A.; Natarajan, K.; Ramasubramaniam, Muthu Rathna Sapabathy.; Deepaknallasamy, K.K.
2017-01-01
Purpose: This paper aims to model and optimize the closed loop supply chain for maximizing the profit by considering the fixed order quantity inventory policy in various sites at multiple periods. Design/methodology/approach: In forward supply chain, a standard inventory policy can be followed when the product moves from manufacturer, distributer, retailer and customer but the inventory in the reverse supply chain of the product with the similar standard policy is very difficult to manage. This model investigates the standard policy of fixed order quantity by considering the three major types of return-recovery pair such as commercial returns, end- of- use returns, end –of- life returns and their inventory positioning at multiple periods. The model is configured as mixed integer linear programming and solved by IBM ILOG CPLEX OPL studio. Findings: To find the performance of the model a numerical example is considered for a product with three Parts (A which of 2nos, B and C) for 12 multiple periods. The results of the analysis show that the manufacturer can know how much should to be manufacture in multiple periods based on Variations of the demand by adopting the FOQ inventory policy at different sites considering its capacity constraints. In addition, it is important how much of parts should be purchased from the supplier at the given 12 periods. Originality/value: A sensitivity analysis is performed to validate the proposed model two parts. First part of the analysis will focus on the inventory of product and parts and second part of analysis focus on profit of the company. The analysis which provides some insights in to the structure of the model.
Optimal inventory policy in a closed loop supply chain system with multiple periods
Energy Technology Data Exchange (ETDEWEB)
Sasi Kumar, A.; Natarajan, K.; Ramasubramaniam, Muthu Rathna Sapabathy.; Deepaknallasamy, K.K.
2017-07-01
Purpose: This paper aims to model and optimize the closed loop supply chain for maximizing the profit by considering the fixed order quantity inventory policy in various sites at multiple periods. Design/methodology/approach: In forward supply chain, a standard inventory policy can be followed when the product moves from manufacturer, distributer, retailer and customer but the inventory in the reverse supply chain of the product with the similar standard policy is very difficult to manage. This model investigates the standard policy of fixed order quantity by considering the three major types of return-recovery pair such as commercial returns, end- of- use returns, end –of- life returns and their inventory positioning at multiple periods. The model is configured as mixed integer linear programming and solved by IBM ILOG CPLEX OPL studio. Findings: To find the performance of the model a numerical example is considered for a product with three Parts (A which of 2nos, B and C) for 12 multiple periods. The results of the analysis show that the manufacturer can know how much should to be manufacture in multiple periods based on Variations of the demand by adopting the FOQ inventory policy at different sites considering its capacity constraints. In addition, it is important how much of parts should be purchased from the supplier at the given 12 periods. Originality/value: A sensitivity analysis is performed to validate the proposed model two parts. First part of the analysis will focus on the inventory of product and parts and second part of analysis focus on profit of the company. The analysis which provides some insights in to the structure of the model.
Optimal inventory policy in a closed loop supply chain system with multiple periods
Directory of Open Access Journals (Sweden)
SasiKumar A.
2017-05-01
Full Text Available Purpose: This paper aims to model and optimize the closed loop supply chain for maximizing the profit by considering the fixed order quantity inventory policy in various sites at multiple periods. Design/methodology/approach: In forward supply chain, a standard inventory policy can be followed when the product moves from manufacturer, distributer, retailer and customer but the inventory in the reverse supply chain of the product with the similar standard policy is very difficult to manage. This model investigates the standard policy of fixed order quantity by considering the three major types of return-recovery pair such as commercial returns, end- of- use returns, end –of- life returns and their inventory positioning at multiple periods. The model is configured as mixed integer linear programming and solved by IBM ILOG CPLEX OPL studio. Findings: To find the performance of the model a numerical example is considered for a product with three Parts (A which of 2nos, B and C for 12 multiple periods. The results of the analysis show that the manufacturer can know how much should to be manufacture in multiple periods based on Variations of the demand by adopting the FOQ inventory policy at different sites considering its capacity constraints. In addition, it is important how much of parts should be purchased from the supplier at the given 12 periods. Originality/value: A sensitivity analysis is performed to validate the proposed model two parts. First part of the analysis will focus on the inventory of product and parts and second part of analysis focus on profit of the company. The analysis which provides some insights in to the structure of the model.
Directory of Open Access Journals (Sweden)
Xiao-qing Zhang
2016-01-01
Full Text Available With the technological developments and rapid changes in demand pattern, diverse varieties of electronic products are entering into the market with reduced lifecycle which leads to the environmental problems. The awareness of electronic products take-back and recovery has been increasing in electronic products supply chains. In this paper, we build a system dynamics model for electronic products closed-loop supply chain distribution network with the old-for-new policy and three electronic products recovery ways, namely, electronic products remanufacturing, electronic component reuse and remanufacturing, and electronic raw material recovery. In the simulation study, we investigate the significance of various factors including the old-for-new policy, collection and remanufacturing, their interactions and the type of their impact on bullwhip, and profitability through sensitivity analysis. Our results instruct that the old-for-new policy and three electronic products recovery ways can reduce the bullwhip effect in the retailers and the distributors and increases the profitability in the closed-loop supply chain distribution network.
A Bi-Objective Green Closed Loop Supply Chain Design Problem with Uncertain Demand
Directory of Open Access Journals (Sweden)
Ming Liu
2018-03-01
Full Text Available With the development of e-commerce, competition among enterprises is becoming fiercer. Furthermore, environmental problems can no longer be ignored. To address these challenges, we devise a green closed loop supply chain (GCLSC with uncertain demand. In the problem, two conflict objectives and recycling the used products are considered. To solve this problem, a mathematical model is formulated with the chance constraint, and the ϵ -constraint method is adapted to obtain the true Pareto front for small sized problems. For larger sized problems, the non-dominated sorting genetic algorithm (NSGA-II and the multi-objective simulated annealing method (MOSA are developed. Numerous computational experiments can help manufacturers make better production and sales plans to keep competitive advantage and protect the environment.
Morin-Duchesne, Alexi
couple sectors d and d' when specific constraints on λ, d, d' and N are satisfied. For the model of critical dense polymers (β = 0) on the strip, the eigenvalues of ρ(DN(λ, u)) were known, but their degeneracies only conjectured. By constructing an isomorphism between the link modules on the strip and a subspace of spin modules of the XXZ model at q = i, we prove this conjecture. We also show that the restriction of the Hamiltonian to any sector d is diagonalizable, and that the XX Hamiltonian has rank 2 Jordan cells when N is even. Finally, we study the Jordan structure of the transfer matrix T N(λ, ν) for periodic boundary conditions. When λ = πa/b and a, b ∈ Z× , the matrix TN(λ, ν) has Jordan blocks between sectors, but also within sectors. The approach using FN admits a generalization to the present case and allows us to probe the Jordan cells that tie different sectors. The rank of these cells exceeds 2 in some cases and can grow indefinitely with N. For the Jordan blocks within a sector, we show that the link modules on the cylinder and the XXZ spin modules are isomorphic except for specific curves in the (q, ν) plane. By using the behavior of the transformation ĩd N in a neighborhood of the critical values (qc, ν c), we explicitly build Jordan partners of rank 2 and discuss the existence of Jordan cells with higher rank. Keywords : phase transitions, Ising model, Potts model, Fortuin-Kasteleyn model, transfer matrix method, XXZ Hamiltonian, logarithmic conformal field theory, Jordan structure.
Prokopy, Max P; Ingersoll, Christopher D; Nordenschild, Edwin; Katch, Frank I; Gaesser, Glenn A; Weltman, Arthur
2008-11-01
Closed-kinetic chain resistance training (CKCRT) of the lower body is superior to open-kinetic chain resistance training (OKCRT) to improve performance parameters (e.g., vertical jump), but the effects of upper-body CKCRT on throwing performance remain unknown. This study compared shoulder strength, power, and throwing velocity changes in athletes training the upper body exclusively with either CKCRT (using a system of ropes and slings) or OKCRT. Fourteen female National Collegiate Athletic Association Division I softball player volunteers were blocked and randomly placed into two groups: CKCRT and OKCRT. Blocking ensured the same number of veteran players and rookies in each training group. Training occurred three times weekly for 12 weeks during the team's supervised off-season program. Olympic, lower-body, core training, and upper-body intensity and volume in OKCRT and CKCRT were equalized between groups. Criterion variables pre- and posttraining included throwing velocity, bench press one-repetition maximum (1RM), dynamic single-leg balance, and isokinetic peak torque and power (PWR) (at 180 degrees x s(-1)) for shoulder flexion, extension, internal rotation, and external rotation (ER). The CKCRT group significantly improved throwing velocity by 2.0 mph (3.4%, p performance. Strength coaches can incorporate upper-body CKCRT without sacrificing gains in maximal strength or performance criteria associated with an athletic open-chain movement such as throwing.
Managing a closed-loop supply chain inventory system with learning effects
Jauhari, Wakhid Ahmad; Dwicahyani, Anindya Rachma; Hendaryani, Oktiviandri; Kurdhi, Nughthoh Arfawi
2018-02-01
In this paper, we propose a closed-loop supply chain model consisting of a retailer and a manufacturer. We intend to investigate the impact of learning in regular production, remanufacturing and reworking. The customer demand is assumed deterministic and will be satisfied from both regular production and remanufacturing process. The return rate of used items depends on quality. We propose a mathematical model with the objective is to maximize the joint total profit by simultaneously determining the length of ordering cycle for the retailer and the number of regular production and remanufacturing cycle. The algorithm is suggested for finding the optimal solution. A numerical example is presented to illustrate the application of using a proposed model. The results show that the integrated model performs better in reducing total cost compared to the independent model. The total cost is most affected by the changes in the values of unit production cost and acceptable quality level. In addition, the changes in the defective items proportion and the fraction of holding costs significantly influence the retailer's ordering period.
One long chain among shorter chains : the Flory approach revisited
Raphaël , E.; Fredrickson , G.; Pincus , P.
1992-01-01
We consider the mean square end-to-end distance of a long chain immersed in a monodisperse, concentrated solution of shorter, chemically identical chains. In contrast with the earlier work of Flory, no simplifying assumption on the wave vector dependence of the effective potential between segments is made. In order to obtain a closed form expression for the dimension of the long chain, we first derive a general expression for the mean square end-to-end distance of a flexible chain with arbitr...
Information Sharing in a Closed-Loop Supply Chain with Asymmetric Demand Forecasts
Directory of Open Access Journals (Sweden)
Pan Zhang
2017-01-01
Full Text Available This paper studies the problem of sharing demand forecast information in a closed-loop supply chain with the manufacturer collecting and remanufacturing. We investigate two scenarios: the “make-to-order” scenario, in which the manufacturer schedules production based on the realized demand, and the “make-to-stock” scenario, in which the manufacturer schedules production before the demand is known. For each scenario, we find that it is possible for the retailer to share his forecast without incentives when the collection efficiency of the manufacturer is high. When the efficiency is moderate, information sharing can be realized by a bargaining mechanism, and when the efficiency is low, non-information sharing is a unique equilibrium. Moreover, the possibility of information sharing in the make-to-stock scenario is higher than that in the make-to-order scenario. In addition, we analyze the impact of demand forecasts’ characteristics on the value of information sharing in both scenarios.
A genetic algorithm approach for solving a closed loop supply chain model
DEFF Research Database (Denmark)
Kannan, G.; Sasikumar, P.; Kannan, Devika
2010-01-01
in reverse logistics is to take back the used products, either under warranty or at the end of use or at the end of lease, so that the products or its parts are appropriately disposed, recycled, reused or remanufactured. In order to overcome this issue, it is necessary to setup a logistics network...... for arising goods flow from end users to manufacturers. In this study, the optimum usage of secondary lead recovered from the spent lead-acid batteries for producing new battery is presented. The disposal in surface or sewage water or land of liquid content of the lead-acid batteries is strictly restricted....... Because of the need for environmental protection and the lack of considerable lead resources, the spent batteries treatment and lead recovery are becoming crucial now-a-days. The objective of this paper is to develop a multi echelon, multi period, multi product closed loop supply chain network model...
A Closed-Loop Supply Chain Problem with Retailing and Recycling Competition
Directory of Open Access Journals (Sweden)
Chuanchao Xu
2014-01-01
Full Text Available We investigate a durable product retailing and recycling problem in a closed-loop supply chain consisting of a single manufacturer and two competitive retailers, in which the manufacturer collects used products via retailers from the consumers and has sufficient channel power over the retailers to act as a Stackelberg leader; the retailers compete in retail products and recycling used products. In order to analyze the impact of retailing and recycling competitions on the profits of the manufacturer and the competitive retailers, two collection models (coordinated collection (Model C and decentralized collection (Model D are established, respectively. Then, based on game theory, we derive the optimal retail price, the optimal repurchase price, and the optimal profits of the manufacturer and the retailers. The managerial insights demonstrate that more intense retailing competition induces the increase of the manufacturer's profits in both forward and reverse channels and retailers' profits in the forward channel and the decrease of retailers' profits in the reverse channel, while more intense recycling competition induces the decrease of the profits of the manufacturer and retailers in both forward and reverse channels. Finally, numerical examples are given to illustrate the effectiveness of the proposed models.
Information services for European pork chains - Closing gaps in information infrastructures
DEFF Research Database (Denmark)
Lehmann, Richard J; Hermansen, John Erik; Fritz, Melanie
2011-01-01
and environmental issues, captured in the term of sustainability. Consumers in their role as final customers, and as a consequence also enterprises within agri-food supply chains, show increasing interest in the characteristics of food, and in turn, on the availability of related information and guarantees....... Enterprises in agri-food supply chains are facing new expectations and are seeking to communicate social, economic and environmental performance of their business to customers within their supply chain and to consumers. New solutions for determination and communication of sustainability are needed...... to measure and evaluate sustainability of products throughout agri-food supply chains. Gained information on product characteristics might be used for decision support within enterprises as well as for communication of sustainable practices to customers and consumers, resulting in increased competitiveness...
Cheng, Long; Hou, Zeng-Guang; Tan, Min; Zhang, W J
2012-10-01
The trajectory tracking problem of a closed-chain five-bar robot is studied in this paper. Based on an error transformation function and the backstepping technique, an approximation-based tracking algorithm is proposed, which can guarantee the control performance of the robotic system in both the stable and transient phases. In particular, the overshoot, settling time, and final tracking error of the robotic system can be all adjusted by properly setting the parameters in the error transformation function. The radial basis function neural network (RBFNN) is used to compensate the complicated nonlinear terms in the closed-loop dynamics of the robotic system. The approximation error of the RBFNN is only required to be bounded, which simplifies the initial "trail-and-error" configuration of the neural network. Illustrative examples are given to verify the theoretical analysis and illustrate the effectiveness of the proposed algorithm. Finally, it is also shown that the proposed approximation-based controller can be simplified by a smart mechanical design of the closed-chain robot, which demonstrates the promise of the integrated design and control philosophy.
Nguyen, Charles C.; Pooran, Farhad J.
1989-01-01
This paper deals with a class of robot manipulators built based on the kinematic chain mechanism (CKCM). This class of CKCM manipulators consists of a fixed and a moving platform coupled together via a number of in-parallel actuators. A closed-form solution is derived for the inverse kinematic problem of a six-degre-of-freedom CKCM manipulator designed to study robotic applications in space. Iterative Newton-Raphson method is employed to solve the forward kinematic problem. Dynamics of the above manipulator is derived using the Lagrangian approach. Computer simulation of the dynamical equations shows that the actuating forces are strongly dependent on the mass and centroid of the robot links.
Development of closed-loop supply chain network in terms of corporate social responsibility.
Pedram, Ali; Pedram, Payam; Yusoff, Nukman Bin; Sorooshian, Shahryar
2017-01-01
Due to the rise in awareness of environmental issues and the depletion of virgin resources, many firms have attempted to increase the sustainability of their activities. One efficient way to elevate sustainability is the consideration of corporate social responsibility (CSR) by designing a closed loop supply chain (CLSC). This paper has developed a mathematical model to increase corporate social responsibility in terms of job creation. Moreover the model, in addition to increasing total CLSC profit, provides a range of strategic decision solutions for decision makers to select a best action plan for a CLSC. A proposed multi-objective mixed-integer linear programming (MILP) model was solved with non-dominated sorting genetic algorithm II (NSGA-II). Fuzzy set theory was employed to select the best compromise solution from the Pareto-optimal solutions. A numerical example was used to validate the potential application of the proposed model. The results highlight the effect of CSR in the design of CLSC.
Directory of Open Access Journals (Sweden)
Erika Machacek
2017-10-01
Full Text Available This article addresses a research gap on the challenges—specifically risk and value—connected to realizing the potential for closing loops for rare earth elements (REE. We develop an analytical framework from conceptual elements of the global value chain (GVC framework and the relational theory of risk to examine several empirical REE industry cases for loop closure. The aim of the paper is to identify how risk–value relationships are constructed by different actors as governance structures form in transactions prior to price setting and how these have impacts on the closure of REE loops. Often, REE loops are not closed, and we find that constructions of the risk–value relationship by industrial actors and by government agencies are unstable as they pursue different motivations, consequently hindering REE loop closure in GVCs. In light of this, we propose that governments mediate against the construction of risk–value relationships by facilitating information on the characteristics of end-of-life materials that qualify these for re-entry into loops.
Efficient dynamic modeling of manipulators containing closed kinematic loops
Ferretti, Gianni; Rocco, Paolo
An approach to efficiently solve the forward dynamics problem for manipulators containing closed chains is proposed. The two main distinctive features of this approach are: the dynamics of the equivalent open loop tree structures (any closed loop can be in general modeled by imposing some additional kinematic constraints to a suitable tree structure) is computed through an efficient Newton Euler formulation; the constraint equations relative to the most commonly adopted closed chains in industrial manipulators are explicitly solved, thus, overcoming the redundancy of Lagrange's multipliers method while avoiding the inefficiency due to a numerical solution of the implicit constraint equations. The constraint equations considered for an explicit solution are those imposed by articulated gear mechanisms and planar closed chains (pantograph type structures). Articulated gear mechanisms are actually used in all industrial robots to transmit motion from actuators to links, while planar closed chains are usefully employed to increase the stiffness of the manipulators and their load capacity, as well to reduce the kinematic coupling of joint axes. The accuracy and the efficiency of the proposed approach are shown through a simulation test.
Sukkel, W.; Hommes, M.
2009-01-01
In their pursuit of growth and professionalisation, the Dutch organic sector focuses primarily on market development. But how do you stimulate the market for organic foods? This is the subject of many research projects concerning market, consumer preferences and the supply chain. These projects focus specifically at consumer purchasing behaviour, product development, supply chain formation and minimising cost price. As a rule, this research takes place in close cooperation with chain actors
Vahdani, Behnam; Tavakkoli-Moghaddam, Reza; Jolai, Fariborz; Baboli, Arman
2013-06-01
This article seeks to offer a systematic approach to establishing a reliable network of facilities in closed loop supply chains (CLSCs) under uncertainties. Facilities that are located in this article concurrently satisfy both traditional objective functions and reliability considerations in CLSC network designs. To attack this problem, a novel mathematical model is developed that integrates the network design decisions in both forward and reverse supply chain networks. The model also utilizes an effective reliability approach to find a robust network design. In order to make the results of this article more realistic, a CLSC for a case study in the iron and steel industry has been explored. The considered CLSC is multi-echelon, multi-facility, multi-product and multi-supplier. Furthermore, multiple facilities exist in the reverse logistics network leading to high complexities. Since the collection centres play an important role in this network, the reliability concept of these facilities is taken into consideration. To solve the proposed model, a novel interactive hybrid solution methodology is developed by combining a number of efficient solution approaches from the recent literature. The proposed solution methodology is a bi-objective interval fuzzy possibilistic chance-constraint mixed integer linear programming (BOIFPCCMILP). Finally, computational experiments are provided to demonstrate the applicability and suitability of the proposed model in a supply chain environment and to help decision makers facilitate their analyses.
Batchelor, Murray T.; Wille, Luc T.
The Table of Contents for the book is as follows: * Preface * Modelling the Immune System - An Example of the Simulation of Complex Biological Systems * Brief Overview of Quantum Computation * Quantal Information in Statistical Physics * Modeling Economic Randomness: Statistical Mechanics of Market Phenomena * Essentially Singular Solutions of Feigenbaum- Type Functional Equations * Spatiotemporal Chaotic Dynamics in Coupled Map Lattices * Approach to Equilibrium of Chaotic Systems * From Level to Level in Brain and Behavior * Linear and Entropic Transformations of the Hydrophobic Free Energy Sequence Help Characterize a Novel Brain Polyprotein: CART's Protein * Dynamical Systems Response to Pulsed High-Frequency Fields * Bose-Einstein Condensates in the Light of Nonlinear Physics * Markov Superposition Expansion for the Entropy and Correlation Functions in Two and Three Dimensions * Calculation of Wave Center Deflection and Multifractal Analysis of Directed Waves Through the Study of su(1,1)Ferromagnets * Spectral Properties and Phases in Hierarchical Master Equations * Universality of the Distribution Functions of Random Matrix Theory * The Universal Chiral Partition Function for Exclusion Statistics * Continuous Space-Time Symmetries in a Lattice Field Theory * Quelques Cas Limites du Problème à N Corps Unidimensionnel * Integrable Models of Correlated Electrons * On the Riemann Surface of the Three-State Chiral Potts Model * Two Exactly Soluble Lattice Models in Three Dimensions * Competition of Ferromagnetic and Antiferromagnetic Order in the Spin-l/2 XXZ Chain at Finite Temperature * Extended Vertex Operator Algebras and Monomial Bases * Parity and Charge Conjugation Symmetries and S Matrix of the XXZ Chain * An Exactly Solvable Constrained XXZ Chain * Integrable Mixed Vertex Models Ftom the Braid-Monoid Algebra * From Yang-Baxter Equations to Dynamical Zeta Functions for Birational Tlansformations * Hexagonal Lattice Directed Site Animals * Direction in
2013-01-01
transition in itinerant electron systems. Phys. Rev. Lett., 95:177201, 2005. [19] Diehl S, Micheli A, Kantian A, Kraus B, Büchler H P, and Zoller P...strongly driven open xxz chain. Phys. Rev. Lett., 107:137201, 2011. [21] Kraus B, Büchler H P, Diehl S, Kantian A, Micheli A, and Zoller P. Preparation
Dual-Recycling Channel Decision in a Closed-Loop Supply Chain with Cost Disruptions
Directory of Open Access Journals (Sweden)
Yanting Huang
2017-11-01
Full Text Available This paper investigates cost disruptions of new and remanufactured products in a closed-loop supply chain where a manufacturer and a third-party collector recycle used products through online-recycling and offline-recycling channels, respectively. We use a Stackelberg game to acquire the equilibrium decisions of dual-recycling and single-recycling channels and analyze how cost disruptions affect the manufacturer’ production and collection strategies. We show that, cost disruption of new products produces a positive impact whilst the remanufacturing cost disruption has a negative impact on collection quantity of used products and negative cost disruptions of both new and remanufactured products could be profitable to the manufacturer. As for the manufacturer’s channel choice, the dual-recycling channel dominates single-recycling channels when new product cost faces positive disruption, because the manufacturer acts as both a buyer and a competitor to the collector and can determine an appropriate acquisition price and transfer price to coordinate the online-offline recycling channel. While if cost disruption of new products is negative, the manufacturer prefers the dual-recycling channel instead of single-recycling channels only if the remanufacturing cost faces large size of negative disruption.
Babaveisi, Vahid; Paydar, Mohammad Mahdi; Safaei, Abdul Sattar
2017-07-01
This study aims to discuss the solution methodology for a closed-loop supply chain (CLSC) network that includes the collection of used products as well as distribution of the new products. This supply chain is presented on behalf of the problems that can be solved by the proposed meta-heuristic algorithms. A mathematical model is designed for a CLSC that involves three objective functions of maximizing the profit, minimizing the total risk and shortages of products. Since three objective functions are considered, a multi-objective solution methodology can be advantageous. Therefore, several approaches have been studied and an NSGA-II algorithm is first utilized, and then the results are validated using an MOSA and MOPSO algorithms. Priority-based encoding, which is used in all the algorithms, is the core of the solution computations. To compare the performance of the meta-heuristics, random numerical instances are evaluated by four criteria involving mean ideal distance, spread of non-dominance solution, the number of Pareto solutions, and CPU time. In order to enhance the performance of the algorithms, Taguchi method is used for parameter tuning. Finally, sensitivity analyses are performed and the computational results are presented based on the sensitivity analyses in parameter tuning.
Magnetocaloric effect in quantum spin-s chains
Directory of Open Access Journals (Sweden)
A. Honecker
2009-01-01
Full Text Available We compute the entropy of antiferromagnetic quantum spin-s chains in an external magnetic field using exact diagonalization and Quantum Monte Carlo simulations. The magnetocaloric effect, i. e., temperature variations during adiabatic field changes, can be derived from the isentropes. First, we focus on the example of the spin-s=1 chain and show that one can cool by closing the Haldane gap with a magnetic field. We then move to quantum spin-s chains and demonstrate linear scaling with s close to the saturation field. In passing, we propose a new method to compute many low-lying excited states using the Lanczos recursion.
Geometrically Constructed Markov Chain Monte Carlo Study of Quantum Spin-phonon Complex Systems
Suwa, Hidemaro
2013-03-01
We have developed novel Monte Carlo methods for precisely calculating quantum spin-boson models and investigated the critical phenomena of the spin-Peierls systems. Three significant methods are presented. The first is a new optimization algorithm of the Markov chain transition kernel based on the geometric weight allocation. This algorithm, for the first time, satisfies the total balance generally without imposing the detailed balance and always minimizes the average rejection rate, being better than the Metropolis algorithm. The second is the extension of the worm (directed-loop) algorithm to non-conserved particles, which cannot be treated efficiently by the conventional methods. The third is the combination with the level spectroscopy. Proposing a new gap estimator, we are successful in eliminating the systematic error of the conventional moment method. Then we have elucidated the phase diagram and the universality class of the one-dimensional XXZ spin-Peierls system. The criticality is totally consistent with the J1 -J2 model, an effective model in the antiadiabatic limit. Through this research, we have succeeded in investigating the critical phenomena of the effectively frustrated quantum spin system by the quantum Monte Carlo method without the negative sign. JSPS Postdoctoral Fellow for Research Abroad
Short-range order in the quantum XXZ honeycomb lattice material BaCo2(PO4)2
Nair, Harikrishnan S.; Brown, J. M.; Coldren, E.; Hester, G.; Gelfand, M. P.; Podlesnyak, A.; Huang, Q.; Ross, K. A.
2018-04-01
We present observations of highly frustrated quasi-two-dimensional (2D) magnetic correlations in the honeycomb lattice layers of the Seff =1 /2 compound γ -BaCo2(PO4)2 (γ -BCPO). Specific heat shows a broad peak comprised of two weak kink features at TN 1˜6 K and TN 2˜3.5 K, the relative weights of which can be modified by sample annealing. Neutron powder diffraction measurements reveal short range quasi-2D order that is established below TN 1 and TN 2, at which two separate, incompatible, short range magnetic orders onset: commensurate antiferromagnetic correlations with correlation length ξc=60 ±2 Å (TN 1) and in quasi-2D helical domains with ξh=350 ±11 Å (TN 2). The ac magnetic susceptibility response lacks frequency dependence, ruling out spin freezing. Inelastic neutron scattering data on γ -BCPO is compared with linear spin wave theory, and two separate parameter regions of the XXZ J1-J2-J3 model with ferromagnetic nearest-neighbor exchange J1 are favored, both near regions of high classical degeneracy. High energy coherent excitations (˜10 meV) persist up to at least 40 K, suggesting strong in-plane correlations persist above TN. These data show that γ -BCPO is a rare highly frustrated, quasi-2D Seff =1 /2 honeycomb lattice material which resists long range magnetic order and spin freezing.
Christy, A. Y.; Fauzi, B. N.; Kurdi, N. A.; Jauhari, W. A.; Saputro, D. R. S.
2017-06-01
The demand of a product is linearly dependent on the retail price and quality of the product. We address a closed-loop supply chain where the manufacturer manufactures products according to the demand and sells them through a retailer in the market. A third party collects the used products from costumers and sends to the manufacturer to increase the quality. If the products can retrieve the original quality, thus the process is called remanufacturing. Not every products can retrieve the original quality, thus manufacturer refurbish this products with lower price. We construct four different scenarios - centralized and decentralized led by manufacturer, retailer, and third party. From the comparison of the result obtained in the numerical example, we conclude that the joint profit obtained under centralized, manufacturer-led, and retailer-led policies is higher than third party-led policy.
Closing loops in agricultural supply chains using multi-objective optimization
Banasik, Aleksander; Kanellopoulos, Argyris; Claassen, G.D.H.; Bloemhof-Ruwaard, Jacqueline M.; Vorst, van der Jack G.A.J.
2017-01-01
Environmental concerns and scarcity of resources encourage decision makers in supply chains to consider alternative production options that include preventing the production of waste streams, and simultaneously reusing and recycling waste materials. Until now, hardly any quantitative modeling
Directory of Open Access Journals (Sweden)
Songi Kim
2016-06-01
Full Text Available The photovoltaic (PV generation system has been widely used since the late 1990s. Considering its lifespan of 20 to 30 years, many end-of-life systems will emerge in the near future. This is why recycling PV systems will be beneficial (and may even be detrimental to both the environment and the economy. Through the recycling process, hazardous by-product substances such as cadmium and lead can be treated properly. Moreover, valuable materials including indium, gallium, and tellurium can be extracted and reused for manufacturing purposes. Even though many studies have dealt with issues related to the PV system and its recycling policy, they lack significant factors regarding the recycling policy. This study analyzes and compares three real cases of manufacturer’s recycling policy, including Deutsche Solar, First Solar, and PV Cycle, from the perspective of a closed-loop supply chain. Two mathematical models are developed to help PV system manufacturers establish supply chain planning and choose suitable recycling policies in consideration of different circumstances. Furthermore, an experimental example of these models will be used to validate and conclude the significance of the models. The results from this study will show that recycling CdTe PV systems is much more efficient than recycling c-Si PV systems and that, in the case of c-Si, it is better to outsource recycling end-of-life systems and dispose of all manufacturing scrap.
International Nuclear Information System (INIS)
Ragnisco, Orlando; Zullo, Federico
2010-01-01
We construct a two-parameter family of Baecklund transformations for the trigonometric classical Gaudin magnet. The approach follows closely the one introduced by Sklyanin and Kuznetsov (1998 J. Phys. A: Math. Gen. 31 2241-51) in a number of seminal papers and takes advantage of the intimate relation between the trigonometric and the rational case. As in the paper by Hone, Kuznetsov and one of the authors (OR) (2001 J. Phys. A: Math. Gen. 34 2477-90) the Baecklund transformations are presented as explicit symplectic maps, starting from their Lax representation. The (expected) connection with the xxz Heisenberg chain is established and the rational (xxx) case is recovered in a suitable limit. It is shown how to obtain a 'physical' transformation mapping real variables into real variables. The interpolating Hamiltonian flow is derived and some numerical iterations of the map are presented.
A Marketing Strategy in a Closed-Loop Supply Chain with Loss-Averse Consumers
Directory of Open Access Journals (Sweden)
Bi-feng Liao
2018-01-01
Full Text Available The importance of remanufacturing system has been extensively investigated in recent years. Taking into account the consumer valuation uncertainty and the demand uncertainty, this paper addresses the issue of closed-loop supply chain with remanufacturing by game theory. We consider two types of consumers in the market: loss-neutral consumers and loss-averse consumers. The loss-neutral consumers are completely rational. The loss-averse consumers, on the other hand, are with losses being more painful than equal-sized gains being pleasant. When multichannel structure can be chosen, the manufacturer has three pricing strategies in direct market: (1 keeping the price high with a small discount, no customers choose the online store; (2 keeping the price high with a moderate discount, only the loss-neutral customers choose the online store; (3 keeping the price low with a big discount, all customers choose the online store. Consumers make up their decisive selections through comparing the price and channel attributes. We introduce utility function for analyzing the market demand and then identify the optimal pricing and channel strategy to maximize the manufacturer’s profit. Finally, the rationality and validities of the proposed model are illustrated by numerical examples, and sensitivity analyses of the parameters are also presented.
International Nuclear Information System (INIS)
Zhou, Chao-Biao; Xiao, Shu-Yuan; Zhang, Cong; Wu, Gang; Ran, Yang-Qiang
2015-01-01
In this paper, by comparing with the thermal entanglement measured by negativity (N), we investigate the measurement-induced disturbance (MID) in a mixed-spin (1/2, 3/2) Heisenberg XXZ model with Dzyaloshinskii–Moriya (DM) interaction and an inhomogeneous external magnetic field. We make a comparison between MID and N, and find that their behaviors present obvious differences following the changes of the exchange constant J, DM interaction D, the uniform magnetic field B and the inhomogeneity of magnetic field b. It is found that J and D broaden the region of MID. At the same time, we notice that, for the case of small D, MID can detect the quantum phase transition near J=0, but not for N. It is also observed that DM interaction and the inhomogeneous external magnetic field play competing roles in enhancing the N and MID in our system. Moreover, we also note D is a more efficient parameter than B and b when adjusting MID under the higher temperature. In addition, we discover that, for the same parameters, the region of MID in our system is larger than the result in mixed-spin (1/2, 1) system.
International Nuclear Information System (INIS)
Hamed Hassani, S; Macris, Nicolas; Urbanke, Ruediger
2012-01-01
We consider a collection of Curie–Weiss (CW) spin systems, possibly with a random field, each of which is placed along the positions of a one-dimensional chain. The CW systems are coupled together by a Kac-type interaction in the longitudinal direction of the chain and by an infinite-range interaction in the direction transverse to the chain. Our motivations for studying this model come from recent findings in the theory of error-correcting codes based on spatially coupled graphs. We find that, although much simpler than the codes, the model studied here already displays similar behavior. We are interested in the van der Waals curve in a regime where the size of each Curie–Weiss model tends to infinity, and the length of the chain and range of the Kac interaction are large but finite. Below the critical temperature, and with appropriate boundary conditions, there appears a series of equilibrium states representing kink-like interfaces between the two equilibrium states of the individual system. The van der Waals curve oscillates periodically around the Maxwell plateau. These oscillations have a period inversely proportional to the chain length and an amplitude exponentially small in the range of the interaction; in other words, the spinodal points of the chain model lie exponentially close to the phase transition threshold. The amplitude of the oscillations is closely related to a Peierls–Nabarro free energy barrier for the motion of the kink along the chain. Analogies to similar phenomena and their possible algorithmic significance for graphical models of interest in coding theory and theoretical computer science are pointed out
Tunnel current across linear homocatenated germanium chains
International Nuclear Information System (INIS)
Matsuura, Yukihito
2014-01-01
The electronic transport properties of germanium oligomers catenating into linear chains (linear Ge chains) have been theoretically studied using first principle methods. The conduction mechanism of a Ge chain sandwiched between gold electrodes was analyzed based on the density of states and the eigenstates of the molecule in a two-probe environment. Like that of silicon chains (Si chains), the highest occupied molecular orbital of Ge chains contains the extended σ-conjugation of Ge 4p orbitals at energy levels close to the Fermi level; this is in contrast to the electronic properties of linear carbon chains. Furthermore, the conductance of a Ge chain is expected to decrease exponentially with molecular length L. The decay constant β, which is defined as e −βL , of a Ge chain is similar to that of a Si chain, whereas the conductance of the Ge chains is higher than that of Si chains even though the Ge–Ge bond length is longer than the Si–Si bond length
Mesoscale simulation of semiflexible chains. I. Endpoint distribution and chain dynamics
Groot, Robert D.
2013-06-01
The endpoint distribution and dynamics of semiflexible fibers are studied by numerical simulation. A brief overview is given over the analytical theory of flexible and semiflexible polymers. In particular, a closed expression is given for the relaxation spectrum of wormlike chains, which determines polymer diffusion and rheology. Next a simulation model for wormlike chains with full hydrodynamic interaction is described, and relations for the bending and torsion modulus are given. Two methods are introduced to include torsion stiffness into the model. The model is validated by simulating single chains in a heat bath, and comparing the endpoint distribution of the chains with established Monte Carlo results. It is concluded that torsion stiffness leads to a slightly shorter effective persistence length for a given bending stiffness. To further validate the simulation model, polymer diffusion is studied for fixed persistence length and varying polymer length N. The diffusion constant shows crossover from Rouse (D ∝ N-1) to reptation behaviour (D ∝ N-2). The terminal relaxation time obtained from the monomer displacement is consistent with the theory of wormlike chains. The probability for chain crossing has also been studied. This probability is so low that it does not influence the present results.
Li, Hui; Wang, Chuanxu; Shang, Meng; Ou, Wei
2017-11-01
In this paper, we examine the influences of vertical and horizontal cooperation models on the optimal decisions and performance of a low-carbon closed-loop supply chain (CLSC) with a manufacturer and two retailers, and study optimal operation in the competitive pricing, competitive the low-carbon promotion, the carbon emission reduction, the used-products collection and the profits. We consider the completely decentralized model, M-R vertical cooperation model, R-R horizontal cooperation model, M-R-R vertical and horizontal cooperation model and completely centralized model, and also identify the optimal decision results and profits. It can be observed from a systematic comparison and numerical analysis that the completely centralized model is best in all optimal decision results among all models. In semi-cooperation, the M-R vertical cooperation model is positive, the R-R horizontal cooperation model is passive, and the positivity of the M-R-R vertical and horizontal cooperation model decreases with competitive intensity increasing in the used-products returning, carbon emissions reduction level, low-carbon promotion effort and the profits of the manufacturer and the entire supply chain.
Putri, Anissa Rianda; Jauhari, Wakhid Ahmad; Rosyidi, Cucuk Nur
2017-11-01
This paper studies a closed-loop supply chain inventory model, where the primary market demand is fulfilled by newly produced products and remanufactured products. We intend to integrate a manufacturer and a collector as a supply chain system. Used items are collected and will be inspected and sorted by the collector, and the return rate of used items is depended upon price and quality factor. Used items that aren't pass this process, will be considered as waste and undergone waste disposal process. Recoverable used items will be sent to the manufacturer for recovery process. This paper applies two types of the recovery process for used products, i.e. remanufacture and refurbish. The refurbished items are sold to a secondary market with lower price than primary market price. Further, the amount of recoverable items depend upon the acceptance level of the returned items. This proposed model gives an optimal solution by maximizing the joint total profit. Moreover, a numerical example is presented to describe the application of the model.
Environmental management the supply chain perspective
Wong, Christina W Y; Lun, Y H Venus; Cheng, T C E
2015-01-01
In view of the increasing quest for environmental management in businesses, this book provides a good reference to firms to understand how they may manage their supply chains to improve business and environmental performance. The book consists of six chapters covering such topics as environmental management, environmental management practices with supply chain efforts, collaborative environmental management, organizational capabilities in environmental management, environmental disclosure, and closed-loop supply chains. The book presents theory-driven discussions on the link between environmental management and business performance in the context of supply chain management. The book will be useful for firms to learn from the research findings and real-life cases to develop plans to implement environmental management practices jointly with supply chain partners.
McMahon, Troy
2014-09-01
© 2014 IEEE. Reachable volumes are a geometric representation of the regions the joints of a robot can reach. They can be used to generate constraint satisfying samples for problems including complicated linkage robots (e.g. closed chains and graspers). They can also be used to assist robot operators and to help in robot design.We show that reachable volumes have an O(1) complexity in unconstrained problems as well as in many constrained problems. We also show that reachable volumes can be computed in linear time and that reachable volume samples can be generated in linear time in problems without constraints. We experimentally validate reachable volume sampling, both with and without constraints on end effectors and/or internal joints. We show that reachable volume samples are less likely to be invalid due to self-collisions, making reachable volume sampling significantly more efficient for higher dimensional problems. We also show that these samples are easier to connect than others, resulting in better connected roadmaps. We demonstrate that our method can be applied to 262-dof, multi-loop, and tree-like linkages including combinations of planar, prismatic and spherical joints. In contrast, existing methods either cannot be used for these problems or do not produce good quality solutions.
McMahon, Troy; Thomas, Shawna; Amato, Nancy M.
2014-01-01
© 2014 IEEE. Reachable volumes are a geometric representation of the regions the joints of a robot can reach. They can be used to generate constraint satisfying samples for problems including complicated linkage robots (e.g. closed chains and graspers). They can also be used to assist robot operators and to help in robot design.We show that reachable volumes have an O(1) complexity in unconstrained problems as well as in many constrained problems. We also show that reachable volumes can be computed in linear time and that reachable volume samples can be generated in linear time in problems without constraints. We experimentally validate reachable volume sampling, both with and without constraints on end effectors and/or internal joints. We show that reachable volume samples are less likely to be invalid due to self-collisions, making reachable volume sampling significantly more efficient for higher dimensional problems. We also show that these samples are easier to connect than others, resulting in better connected roadmaps. We demonstrate that our method can be applied to 262-dof, multi-loop, and tree-like linkages including combinations of planar, prismatic and spherical joints. In contrast, existing methods either cannot be used for these problems or do not produce good quality solutions.
Structural transformations of carbon chains inside nanotubes
International Nuclear Information System (INIS)
Warner, Jamie H.; Ruemmeli, Mark H.; Bachmatiuk, Alicja; Buechner, Bernd
2010-01-01
In situ aberration-corrected high-resolution transmission electron microscopy is used to examine the structural transformations of carbon chains that occur in the interior region of carbon nanotubes. We find electron-beam irradiation leads to the formation of two-dimensional carbon structures that are freely mobile inside the nanotube. The inner diameter of the nanotube influences the structural transformations of the carbon chains. As the diameter of the nanotube increases, electron-beam irradiation leads to curling of the chains and eventually the formation of closed looped structures. The closed looped structures evolve into spherical fullerenelike structures that exhibit translational motion inside the nanotubes and also coalesce to form larger nanotube structures. These results demonstrate the use of carbon nanotubes as test tubes for growing small carbon nanotubes within the interior by using only electron-beam irradiation at 80 kV.
q-bosons, Toda lattice, Pieri rules and Baxter q-operator
International Nuclear Information System (INIS)
Duval, Antoine; Pasquier, Vincent
2016-01-01
We use the Pieri rules to recover the q-boson model and show it is equivalent to a discretized version of the relativistic Toda chain. We identify its semi infinite transfer matrix and the corresponding Baxter Q-matrix with half vertex operators related by an ω-duality transformation. We observe that the scalar product of two higher spin XXZ wave functions can be expressed with a Gaudin determinant. (paper)
Verification of Open Interactive Markov Chains
Brazdil, Tomas; Hermanns, Holger; Krcal, Jan; Kretinsky, Jan; Rehak, Vojtech
2012-01-01
Interactive Markov chains (IMC) are compositional behavioral models extending both labeled transition systems and continuous-time Markov chains. IMC pair modeling convenience - owed to compositionality properties - with effective verification algorithms and tools - owed to Markov properties. Thus far however, IMC verification did not consider compositionality properties, but considered closed systems. This paper discusses the evaluation of IMC in an open and thus compositional interpretation....
Boosting nearest-neighbour to long-range integrable spin chains
International Nuclear Information System (INIS)
Bargheer, Till; Beisert, Niklas; Loebbert, Florian
2008-01-01
We present an integrability-preserving recursion relation for the explicit construction of long-range spin chain Hamiltonians. These chains are generalizations of the Haldane–Shastry and Inozemtsev models and they play an important role in recent advances in string/gauge duality. The method is based on arbitrary nearest-neighbour integrable spin chains and it sheds light on the moduli space of deformation parameters. We also derive the closed chain asymptotic Bethe equations. (letter)
Directory of Open Access Journals (Sweden)
Jie Gao
2016-01-01
Full Text Available The dual-channel closed-loop supply chain (CLSC which is composed of one manufacturer and one retailer under uncertain demand of an indirect channel is constructed. In this paper, we establish three pricing models under decentralized decision making, namely, the Nash game between the manufacturer and the retailer, the manufacturer-Stackelberg game, and the retailer-Stackelberg game, to investigate pricing decisions of the CLSC in which the manufacturer uses the direct channel and indirect channel to sell products and entrusts the retailer to collect the used products. We numerically analyze the impact of customer acceptance of the direct channel (θ on pricing decisions and excepted profits of the CLSC. The results show that when the variable θ changes in a certain range, the wholesale price, retail price, and expected profits of the retailer all decrease when θ increases, while the direct online sales price and manufacturer’s expected profits in the retailer-Stackelberg game all increase when θ increases. However, the optimal recycling transfer price and optimal acquisition price of used product are unaffected by θ.
Solan, Eilon; Vieille, Nicolas
2015-01-01
We study irreducible time-homogenous Markov chains with finite state space in discrete time. We obtain results on the sensitivity of the stationary distribution and other statistical quantities with respect to perturbations of the transition matrix. We define a new closeness relation between transition matrices, and use graph-theoretic techniques, in contrast with the matrix analysis techniques previously used.
Entanglement entropy of excited states
International Nuclear Information System (INIS)
Alba, Vincenzo; Fagotti, Maurizio; Calabrese, Pasquale
2009-01-01
We study the entanglement entropy of a block of contiguous spins in excited states of spin chains. We consider the XY model in a transverse field and the XXZ Heisenberg spin chain. For the latter, we developed a numerical application of the algebraic Bethe ansatz. We find two main classes of states with logarithmic and extensive behavior in the dimension of the block, characterized by the properties of excitations of the state. This behavior can be related to the locality properties of the Hamiltonian having a given state as the ground state. We also provide several details of the finite size scaling
Scattering of waves by impurities in precompressed granular chains.
Martínez, Alejandro J; Yasuda, Hiromi; Kim, Eunho; Kevrekidis, P G; Porter, Mason A; Yang, Jinkyu
2016-05-01
We study scattering of waves by impurities in strongly precompressed granular chains. We explore the linear scattering of plane waves and identify a closed-form expression for the reflection and transmission coefficients for the scattering of the waves from both a single impurity and a double impurity. For single-impurity chains, we show that, within the transmission band of the host granular chain, high-frequency waves are strongly attenuated (such that the transmission coefficient vanishes as the wavenumber k→±π), whereas low-frequency waves are well-transmitted through the impurity. For double-impurity chains, we identify a resonance-enabling full transmission at a particular frequency-in a manner that is analogous to the Ramsauer-Townsend (RT) resonance from quantum physics. We also demonstrate that one can tune the frequency of the RT resonance to any value in the pass band of the host chain. We corroborate our theoretical predictions both numerically and experimentally, and we directly observe almost complete transmission for frequencies close to the RT resonance frequency. Finally, we show how this RT resonance can lead to the existence of reflectionless modes in granular chains (including disordered ones) with multiple double impurities.
Li, Hui; Wang, Chuanxu; Shang, Meng; Ou, Wei
2017-01-01
In this paper, we examine the influences of vertical and horizontal cooperation models on the optimal decisions and performance of a low-carbon closed-loop supply chain (CLSC) with a manufacturer and two retailers, and study optimal operation in the competitive pricing, competitive the low-carbon promotion, the carbon emission reduction, the used-products collection and the profits. We consider the completely decentralized model, M-R vertical cooperation model, R-R horizontal cooperation model, M-R-R vertical and horizontal cooperation model and completely centralized model, and also identify the optimal decision results and profits. It can be observed from a systematic comparison and numerical analysis that the completely centralized model is best in all optimal decision results among all models. In semi-cooperation, the M-R vertical cooperation model is positive, the R-R horizontal cooperation model is passive, and the positivity of the M-R-R vertical and horizontal cooperation model decreases with competitive intensity increasing in the used-products returning, carbon emissions reduction level, low-carbon promotion effort and the profits of the manufacturer and the entire supply chain. PMID:29104268
Directory of Open Access Journals (Sweden)
Hui Li
2017-11-01
Full Text Available In this paper, we examine the influences of vertical and horizontal cooperation models on the optimal decisions and performance of a low-carbon closed-loop supply chain (CLSC with a manufacturer and two retailers, and study optimal operation in the competitive pricing, competitive the low-carbon promotion, the carbon emission reduction, the used-products collection and the profits. We consider the completely decentralized model, M-R vertical cooperation model, R-R horizontal cooperation model, M-R-R vertical and horizontal cooperation model and completely centralized model, and also identify the optimal decision results and profits. It can be observed from a systematic comparison and numerical analysis that the completely centralized model is best in all optimal decision results among all models. In semi-cooperation, the M-R vertical cooperation model is positive, the R-R horizontal cooperation model is passive, and the positivity of the M-R-R vertical and horizontal cooperation model decreases with competitive intensity increasing in the used-products returning, carbon emissions reduction level, low-carbon promotion effort and the profits of the manufacturer and the entire supply chain.
Exact expectation values of local fields in the quantum sine-Gordon model
International Nuclear Information System (INIS)
Lukyanov, S.; Rossijskaya Akademiya Nauk, Chernogolovka; Zamolodchikov, A.; Rossijskaya Akademiya Nauk, Chernogolovka
1997-01-01
We propose an explicit expression for vacuum expectation values left angle e iaφ right angle of the exponential fields in the sine-Gordon model. Our expression agrees both with semi-classical results in the sine-Gordon theory and with perturbative calculations in the massive Thirring model. We use this expression to make new predictions about the large-distance asymptotic form of the two-point correlation function in the XXZ spin chain. (orig.)
Institute of Scientific and Technical Information of China (English)
聂佳佳
2012-01-01
Reverse logistics (e. g. product remanufacturing or recycling) practices can not only reduce the natural resources needed and the waste produced, but also help reduce the environmental burden. It is not unusual to see in practice the used-product collection activity contracted by a manufacturer to a third party, who is engaged only in the collection of the used products from the market. For example, in the automobile industry, used-product collection activities for the original equipment manufacturers are handled by some independent third parties. Recently, in the United States the "big three" auto manufacturers started to invest in joint research and remanufacturing partnerships with dismantling centers to benefit from their experiences and economics of scale. With the independent third parties joining the closed-loop supply chain, it becomes more difficult to study the closed-loop supply chain for of the increasing number supply chain members. In the third-party collecting closed-loop supply chain, there are several channels structures including no strategic alliance, strategic alliance between the retailer and the manufacturer, strategic alliance between the retailer and the third-party and strategic alliance between the manufacturer and the third-party. In this research, the aim is to examine the effect of these channel structures on the performance of members in a third-party collecting closed-loop supply chain. First, this paper adopts the game theory to develop four models of closed-loop supply chain. Second, the optimal retail prices, wholesale prices, return rates and profits of these models are derived. Third, these four models are compared with each other. Fourth, the effect of system parameters on the performance of members is researched with numerical simulation and some new findings are revealed. This study shows five interesting results. First, the retail price is the highest, the demand is the least and return rate is the lowest in the no strategic
The role of chain carriers in fusion reaction kinetics
International Nuclear Information System (INIS)
Harms, A.A.; Krenciglowa, E.M.
1980-01-01
The role of chain carriers as contributors to multiplicative closed cycles in advanced fusion fuels is examined. Emphasis is placed on rate processes which can be used to characterize critical/supercritical/subcritical tendencies of arbitrary closed fusion cycles. Temporal trajectories for the chain carriers which describe both increasing and decreasing multiplicative processes have been found to exist and identified according to their fusion fuel cycle characteristics. Practical criteria to ensure the attainment of steady-state fusion reaction processes have been formulated in terms of fusion reaction rate relationships. (author)
Spin diffusion from an inhomogeneous quench in an integrable system.
Ljubotina, Marko; Žnidarič, Marko; Prosen, Tomaž
2017-07-13
Generalized hydrodynamics predicts universal ballistic transport in integrable lattice systems when prepared in generic inhomogeneous initial states. However, the ballistic contribution to transport can vanish in systems with additional discrete symmetries. Here we perform large scale numerical simulations of spin dynamics in the anisotropic Heisenberg XXZ spin 1/2 chain starting from an inhomogeneous mixed initial state which is symmetric with respect to a combination of spin reversal and spatial reflection. In the isotropic and easy-axis regimes we find non-ballistic spin transport which we analyse in detail in terms of scaling exponents of the transported magnetization and scaling profiles of the spin density. While in the easy-axis regime we find accurate evidence of normal diffusion, the spin transport in the isotropic case is clearly super-diffusive, with the scaling exponent very close to 2/3, but with universal scaling dynamics which obeys the diffusion equation in nonlinearly scaled time.
Quantum-memory-assisted entropic uncertainty in spin models with Dzyaloshinskii-Moriya interaction
Huang, Zhiming
2018-02-01
In this article, we investigate the dynamics and correlations of quantum-memory-assisted entropic uncertainty, the tightness of the uncertainty, entanglement, quantum correlation and mixedness for various spin chain models with Dzyaloshinskii-Moriya (DM) interaction, including the XXZ model with DM interaction, the XY model with DM interaction and the Ising model with DM interaction. We find that the uncertainty grows to a stable value with growing temperature but reduces as the coupling coefficient, anisotropy parameter and DM values increase. It is found that the entropic uncertainty is closely correlated with the mixedness of the system. The increasing quantum correlation can result in a decrease in the uncertainty, and the robustness of quantum correlation is better than entanglement since entanglement means sudden birth and death. The tightness of the uncertainty drops to zero, apart from slight volatility as various parameters increase. Furthermore, we propose an effective approach to steering the uncertainty by weak measurement reversal.
Directory of Open Access Journals (Sweden)
Daoming Dai
2017-10-01
Full Text Available This paper constructs a continuous dual-channel closed-loop supply chain (DCLSC model with delayed decision under government intervention. The existence conditions of the local stability of the equilibrium point are discussed. We analyze the influence of delay parameters, the adjustment speed of wholesale price, recovery rate of waste products, direct price, carbon quota subsidy, and carbon tax on the stability and complexity of model by using bifurcation diagram, entropy diagram, attractor, and time series diagram and so on. Besides, the delay feedback control method is adopted to control the unstable or chaotic system effectively. The main conclusions of this paper show that the variables mentioned above must be within a reasonable range. Otherwise, the model will lose stability or enter chaos. The government can effectively adjust manufacturers' profit through carbon tax and carbon quota subsidy, and encourage manufacturers to reduce carbon emissions and increase the remanufacturing of waste products.
Precast Pearl-Chain concrete arch bridges
DEFF Research Database (Denmark)
Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup
2015-01-01
A Pearl-Chain Bridge is a closed-spandrel arch bridge consisting of a number of straight pre-fabricated so called Super-Light Deck elements put together in an arch shape by post-tensioning cables. Several Pearl-Chain arches can be positioned adjacent to each other by a crane to achieve a bridge...... of a desired width. On top of the arch is a filling material to level out the surface of the above road. The filling only transfers vertical loads to the arch. The geometry and material properties of Super-Light Decks are presented, and we refer to several fullscale tests of Pearl-Chain arches where...... the technology was used. We also study other important components and details in the Pearl-Chain Bridge concept and review the effects of different types of loads. A theoretical case study of a circular 30 m span Pearl-Chain Bridge is presented showing the influence of a number of parameters: The number of post...
Supply chain performance within agri-food sector
Directory of Open Access Journals (Sweden)
Dinu Daniela Magdalena
2016-01-01
Full Text Available By setting the goals of this scientific paper has been outlined the research methodology. Thus were developed conclusion, and by using the methods, procedures, techniques, rules and tools and know-how has been demonstrated the central hypothesis: 'Inside the agri-food supply chain is created value through operations and logistics activities.' The value created leads to competitive advantages in order to identify companies within market, gaining loyal consumers. The article presents the components of agri-food supply chain, the main Key Performance Indicators measuring its performance, the difference between a traditional supply chain and sustainable supply chain by analyzing the waste management component. In order to get professional expertise referring to Key Performance Indicators a quantitative research has been organized. In closing the article present the development strategies of agri-food supply chain.
Entanglement entropy in random quantum spin-S chains
International Nuclear Information System (INIS)
Saguia, A.; Boechat, B.; Continentino, M. A.; Sarandy, M. S.
2007-01-01
We discuss the scaling of entanglement entropy in the random singlet phase (RSP) of disordered quantum magnetic chains of general spin S. Through an analysis of the general structure of the RSP, we show that the entanglement entropy scales logarithmically with the size of a block, and we provide a closed expression for this scaling. This result is applicable for arbitrary quantum spin chains in the RSP, being dependent only on the magnitude S of the spin. Remarkably, the logarithmic scaling holds for the disordered chain even if the pure chain with no disorder does not exhibit conformal invariance, as is the case for Heisenberg integer-spin chains. Our conclusions are supported by explicit evaluations of the entanglement entropy for random spin-1 and spin-3/2 chains using an asymptotically exact real-space renormalization group approach
Takizawa, Yuumi; Shimomura, Takeshi; Miura, Toshiaki
2013-05-23
We study the initial nucleation dynamics of poly(3-hexylthiophene) (P3HT) in solution, focusing on the relationship between the ordering process of main chains and that of side chains. We carried out Langevin dynamics simulation and found that the initial nucleation processes consist of three steps: the ordering of ring orientation, the ordering of main-chain vectors, and the ordering of side chains. At the start, the normal vectors of thiophene rings aligned in a very short time, followed by alignment of main-chain end-to-end vectors. The flexible side-chain ordering took almost 5 times longer than the rigid-main-chain ordering. The simulation results indicated that the ordering of side chains was induced after the formation of the regular stack structure of main chains. This slow ordering dynamics of flexible side chains is one of the factors that cause anisotropic nuclei growth, which would be closely related to the formation of nanofiber structures without external flow field. Our simulation results revealed how the combined structure of the planar and rigid-main-chain backbones and the sparse flexible side chains lead to specific ordering behaviors that are not observed in ordinary linear polymer crystallization processes.
Analytical expression for the correlation function of a hard sphere chain fluid
Chang, Jaeeon; Kim, Hwayong
A closed form expression is given for the correlation function of flexible hard sphere chain fluid. A set of integral equations obtained from Wertheim's multidensity Ornstein-Zernike integral equation theory with the polymer Percus-Yevick ideal chain approximation is considered. Applying the Laplace transformation method to the integral equations and then solving the resulting equations algebraically, the Laplace transforms of individual correlation functions are obtained. By inverse Laplace transformation the inter- and intramolecular radial distribution functions (RDFs) are obtained in closed forms up to 3D(D is segment diameter). These analytical expressions for the RDFs would be useful in developing the perturbation theory of chain fluids.
High-field spin dynamics of antiferromagnetic quantum spin chains
DEFF Research Database (Denmark)
Enderle, M.; Regnault, L.P.; Broholm, C.
2000-01-01
present recent work on the high-field spin dynamics of the S = I antiferromagnetic Heisenberg chains NENP (Haldane ground state) and CsNiCl3 (quasi-1D HAF close to the quantum critical point), the uniform S = 1/2 chain CTS, and the spin-Peierls system CuGeO3. (C) 2000 Elsevier Science B,V. All rights...
On the quantum inverse scattering problem
International Nuclear Information System (INIS)
Maillet, J.M.; Terras, V.
2000-01-01
A general method for solving the so-called quantum inverse scattering problem (namely the reconstruction of local quantum (field) operators in term of the quantum monodromy matrix satisfying a Yang-Baxter quadratic algebra governed by an R-matrix) for a large class of lattice quantum integrable models is given. The principal requirement being the initial condition (R(0)=P, the permutation operator) for the quantum R-matrix solving the Yang-Baxter equation, it applies not only to most known integrable fundamental lattice models (such as Heisenberg spin chains) but also to lattice models with arbitrary number of impurities and to the so-called fused lattice models (including integrable higher spin generalizations of Heisenberg chains). Our method is then applied to several important examples like the sl n XXZ model, the XYZ spin-((1)/(2)) chain and also to the spin-s Heisenberg chains
Social network analysis and supply chain management
Directory of Open Access Journals (Sweden)
Raúl Rodríguez Rodríguez
2016-01-01
Full Text Available This paper deals with social network analysis and how it could be integrated within supply chain management from a decision-making point of view. Even though the benefits of using social analysis have are widely accepted at both academic and industry/services context, there is still a lack of solid frameworks that allow decision-makers to connect the usage and obtained results of social network analysis – mainly both information and knowledge flows and derived results- with supply chain management objectives and goals. This paper gives an overview of social network analysis, the main social network analysis metrics, supply chain performance and, finally, it identifies how future frameworks could close the gap and link the results of social network analysis with the supply chain management decision-making processes.
On the particle-hole symmetry of the fermionic spinless Hubbard model in D=1
Directory of Open Access Journals (Sweden)
M.T. Thomaz
2014-06-01
Full Text Available We revisit the particle-hole symmetry of the one-dimensional (D=1 fermionic spinless Hubbard model, associating that symmetry to the invariance of the Helmholtz free energy of the one-dimensional spin-1/2 XXZ Heisenberg model, under reversal of the longitudinal magnetic field and at any finite temperature. Upon comparing two regimes of that chain model so that the number of particles in one regime equals the number of holes in the other, one finds that, in general, their thermodynamics is similar, but not identical: both models share the specific heat and entropy functions, but not the internal energy per site, the first-neighbor correlation functions, and the number of particles per site. Due to that symmetry, the difference between the first-neighbor correlation functions is proportional to the z-component of magnetization of the XXZ Heisenberg model. The results presented in this paper are valid for any value of the interaction strength parameter V, which describes the attractive/null/repulsive interaction of neighboring fermions.
Implementing a real-time chain of segmentation of images on a multi-FPGA architecture
Akil, Mohamed; Zahirazami, Shahram
1998-03-01
In this paper we present the study and the implementation of an optimized chain of segmentation operators. We implemented this chain in real time, consisting of a Deriche contour detection, double threshold, closing of contours and finally region labeling, on a multi-FPGA architecture. This architecture has four processing FPGAs and four memory modules. Deriche operator, closing of contours and labeling occupy each one an FPGA. Double threshold and detection of the extremities filled partially the forth FPGA. The slowest component of the chain is Deriche operator which can go up to 11.4 Mhz, assuring the process of an image every 40 ms. Deriche operator tries to extract the contours by assuming that a contour is a step super positioned by a white gaussian noise. Our implementation consists of a smoothing part of four second order filters and a Sobel as a derivation part. The second order filters are causal and non-causal horizontal and vertical operators. The gradient image passes through a double threshold filter to select the real contours and the crests and the background pixels. Closing of contours eliminates the false crests and finally the labeling gives a unique label to each closed region. The latency of the chain is in the order of three images. This implementation shows the efficiency of the chain and also it demonstrates the capabilities of our architecture as a prototyping system.
Forouzanfar, F.; Tavakkoli-Moghaddam, R.; Bashiri, M.; Baboli, A.; Hadji Molana, S. M.
2017-11-01
This paper studies a location-routing-inventory problem in a multi-period closed-loop supply chain with multiple suppliers, producers, distribution centers, customers, collection centers, recovery, and recycling centers. In this supply chain, centers are multiple levels, a price increase factor is considered for operational costs at centers, inventory and shortage (including lost sales and backlog) are allowed at production centers, arrival time of vehicles of each plant to its dedicated distribution centers and also departure from them are considered, in such a way that the sum of system costs and the sum of maximum time at each level should be minimized. The aforementioned problem is formulated in the form of a bi-objective nonlinear integer programming model. Due to the NP-hard nature of the problem, two meta-heuristics, namely, non-dominated sorting genetic algorithm (NSGA-II) and multi-objective particle swarm optimization (MOPSO), are used in large sizes. In addition, a Taguchi method is used to set the parameters of these algorithms to enhance their performance. To evaluate the efficiency of the proposed algorithms, the results for small-sized problems are compared with the results of the ɛ-constraint method. Finally, four measuring metrics, namely, the number of Pareto solutions, mean ideal distance, spacing metric, and quality metric, are used to compare NSGA-II and MOPSO.
Detailed solution to a complex kinematics chain manipulator
International Nuclear Information System (INIS)
March-Leuba, S.; Jansen, J.F.; Kress, R.L.; Babcock, S.M.
1992-01-01
This paper presents a relatively simple method based on planar geometry to analyze the inverse kinematics for closed kinematics chain (CKC) mechanisms. Although the general problem and method of approach are well defined, the study of the inverse kinematics of a closed-chain mechanism is a very complicated one. The current methodology allows closed-form solutions to be found, if a solution exists, for the displacements and velocities of all manipulator joints. Critical design parameters can be identified and optimized by using symbolic models. This paper will focus on planar closed-chain structures extended with a rotational base. However, with open and CKC mechanisms combined in different planes, the extension to the case is straightforward. Further, real-time algorithms are developed that can be handled by existing microprocessor technology. To clarify the methodology, the Soldier Robot Interface Project (SRIP) manipulator is analyzed, and a graphic simulation is presented as a verification of the results. This manipulator has 17 links, 24 one-degree-of-freedom (DOF) joints, and 7 CKC loops working in a plane and a rotational base, which determine its 3 DOFs. The SRIP manipulator allows a decoupled linear motion along the vertical or horizontal directions using only one of its linear actuators. The symbolic solution for the inverse kinematics allows optimization to be performed to further decouple the Cartesian motions by changing link lengths of the manipulator. The conclusion achieved by the optimization is that only two link lengths need to be changed to tune the manipulator for a perfect decoupling at each area of the workspace
Directory of Open Access Journals (Sweden)
Mbarek Elbounjimi
2015-11-01
Full Text Available Closed-loop supply chain network design is a critical issue due to its impact on both economic and environmental performances of the supply chain. In this paper, we address the problem of designing a multi-echelon, multi-product and capacitated closed-loop supply chain network. First, a mixed-integer linear programming formulation is developed to maximize the total profit. The main contribution of the proposed model is addressing two economic viability issues of closed-loop supply chain. The first issue is the collection of sufficient quantity of end-of-life products are assured by retailers against an acquisition price. The second issue is exploiting the benefits of colocation of forward facilities and reverse facilities. The presented model is solved by LINGO for some test problems. Computational results and sensitivity analysis are conducted to show the performance of the proposed model.
Directory of Open Access Journals (Sweden)
Soumita Kundu
2014-01-01
Full Text Available We study a closed-loop supply chain involving a manufacturing facility and a remanufacturing facility. The manufacturer satisfies stochastic market demand by remanufacturing the used product into “as-new” one and producing new products from raw material in the remanufacturing facility and the manufacturing facility, respectively. The remanufacturing cost depends on the quality of used product. The problem is maximizing the manufacturer’s expected profit by jointly determining the collected quantity of used product and the ordered quantity of raw material. Following that we analyze the model with a fill rate constraint and a budget constraint separately and then with both the constraints. Next, to handle the imprecise nature of some parameters of the model, we develop the model with both constraints in bifuzzy environment. Finally numerical examples are presented to illustrate the models. The sensitivity analysis is also conducted to generate managerial insight.
Buyer focus : Evaluation of a new concept for supply chain integration
van der Vaart, T; van Donk, DP
2004-01-01
The goal of integrated supply chains is to remove barriers to ease the flow of materials and information. This article concentrates on an important barrier: shared resources in a supply chain. The removal of these shared resources is closely related to the recently introduced concept of buyer focus.
Buyer focus : evaluation of a new concept for supply chain integration
Vaart, Taco van der; Donk, Dirk Pieter van
2003-01-01
The goal of integrated supply chains is to remove barriers to ease the flow of materials and information. This article concentrates on an important barrier: shared resources in a supply chain. The removal of these shared resources is closely related to the recently introduced concept of buyer focus.
Bayesian analysis for reversible Markov chains
Diaconis, P.; Rolles, S.W.W.
2006-01-01
We introduce a natural conjugate prior for the transition matrix of a reversible Markov chain. This allows estimation and testing. The prior arises from random walk with reinforcement in the same way the Dirichlet prior arises from Pólya’s urn. We give closed form normalizing constants, a simple
International Nuclear Information System (INIS)
Luo, Da-Wei; Xu, Jing-Bo
2015-01-01
We use an alternative method to investigate the quantum criticality at zero and finite temperature using trace distance along with the density matrix renormalization group. It is shown that the average correlation measured by the trace distance between the system block and environment block in a DMRG sweep is able to detect the critical points of quantum phase transitions at finite temperature. As illustrative examples, we study spin-1 XXZ chains with uniaxial single-ion-type anisotropy and the Heisenberg spin chain with staggered coupling and external magnetic field. It is found that the trace distance shows discontinuity at the critical points of quantum phase transition and can be used as an indicator of QPTs
Surface free energy for systems with integrable boundary conditions
International Nuclear Information System (INIS)
Goehmann, Frank; Bortz, Michael; Frahm, Holger
2005-01-01
The surface free energy is the difference between the free energies for a system with open boundary conditions and the same system with periodic boundary conditions. We use the quantum transfer matrix formalism to express the surface free energy in the thermodynamic limit of systems with integrable boundary conditions as a matrix element of certain projection operators. Specializing to the XXZ spin-1/2 chain we introduce a novel 'finite temperature boundary operator' which characterizes the thermodynamical properties of surfaces related to integrable boundary conditions
A Model for Sustainable Value Creation in Supply Chain
KORDİTABAR, Seyed Behzad
2015-01-01
Abstract. In order to survive, every company needs to achieve sustainable profitability, which is impossible unless there is sustainable value creation. Regarding the fact that sustainability is closely related with concepts of supply chain management, the present paper intends to propose through a conceptual theorization approach a new comprehensive model drawing on concepts of value creation and sustainability from the perspective of supply chain, specifying the dimensions contributing to s...
Markov chains and mixing times
Levin, David A
2017-01-01
Markov Chains and Mixing Times is a magical book, managing to be both friendly and deep. It gently introduces probabilistic techniques so that an outsider can follow. At the same time, it is the first book covering the geometric theory of Markov chains and has much that will be new to experts. It is certainly THE book that I will use to teach from. I recommend it to all comers, an amazing achievement. -Persi Diaconis, Mary V. Sunseri Professor of Statistics and Mathematics, Stanford University Mixing times are an active research topic within many fields from statistical physics to the theory of algorithms, as well as having intrinsic interest within mathematical probability and exploiting discrete analogs of important geometry concepts. The first edition became an instant classic, being accessible to advanced undergraduates and yet bringing readers close to current research frontiers. This second edition adds chapters on monotone chains, the exclusion process and hitting time parameters. Having both exercises...
A Martingale Decomposition of Discrete Markov Chains
DEFF Research Database (Denmark)
Hansen, Peter Reinhard
We consider a multivariate time series whose increments are given from a homogeneous Markov chain. We show that the martingale component of this process can be extracted by a filtering method and establish the corresponding martingale decomposition in closed-form. This representation is useful fo...
Responsible chain management: a capability assessment framework
de Bakker, F.G.A.; Nijhof, A.
2002-01-01
In recent years, increased attention has been paid to issues of responsibility across the entire product lifecyle. Responsible behaviour of organizations in the product chain is dependent on the actions of other parties such as suppliers and customers. Only through co-operation and close interaction
Responsible chain management: A capability assessment framework
de Bakker, F.G.A.; Nijhof, A.H.J.
2002-01-01
In recent years, increased attention has been paid to issues of responsibility across the entire product lifecycle. Responsible behaviour of organizations in the product chain is dependent on the actions of other parties such as suppliers and customers. Only through co-operation and close
Kinematic Chains in Ski Jumping In-run Posture.
Janurová, Eva; Janura, Miroslav; Cabell, Lee; Svoboda, Zdeněk; Vařeka, Ivan; Elfmark, Milan
2013-12-18
The concept of kinematic chains has been systematically applied to biological systems since the 1950s. The course of a ski jump can be characterized as a change between closed and open kinematic chains. The purpose of this study was to determine a relationship between adjacent segments within the ski jumper's body's kinematic chain during the in-run phase of the ski jump. The in-run positions of 267 elite male ski jumpers who participated in the FIS World Cup events in Innsbruck, Austria, between 1992 and 2001 were analyzed (656 jumps). Two-dimensional (2-D) kinematic data were collected from the bodies of the subjects. Relationships between adjacent segments of the kinematic chain in the ski jumper's body at the in-run position are greater nearer the chain's ground contact. The coefficient of determination between the ankle and knee joint angles is 0.67. Changes in the segments' positions in the kinematic chain of the ski jumper's body are stable during longitudinal assessment. Changes in shank and thigh positions, in the sense of increase or decrease, are the same.
Corrections to scaling for block entanglement in massive spin chains
International Nuclear Information System (INIS)
Calabrese, Pasquale; Cardy, John; Peschel, Ingo
2010-01-01
We consider the Rényi entropies S n in one-dimensional massive integrable models diagonalizable by means of corner transfer matrices (such as Heisenberg and Ising spin chains). By means of explicit examples and using the relation of the corner transfer matrix with the Virasoro algebra, we show that close to a conformally invariant critical point, when the correlation length ξ is finite but large, the corrections to the scaling are of the unusual form ξ −x/n , with x the dimension of a relevant operator in the conformal theory. This is reminiscent of the results for gapless chains and should be valid for any massive one-dimensional model close to a conformal critical point
Statistical properties of multi-theta polymer chains
Uehara, Erica; Deguchi, Tetsuo
2018-04-01
We study statistical properties of polymer chains with complex structures whose chemical connectivities are expressed by graphs. The multi-theta curve of m subchains with two branch points connected by them is one of the simplest graphs among those graphs having closed paths, i.e. loops. We denoted it by θm , and for m = 2 it is given by a ring. We derive analytically the pair distribution function and the scattering function for the θm -shaped polymer chains consisting of m Gaussian random walks of n steps. Surprisingly, it is shown rigorously that the mean-square radius of gyration for the Gaussian θm -shaped polymer chain does not depend on the number m of subchains if each subchain has the same fixed number of steps. For m = 3 we show the Kratky plot for the theta-shaped polymer chain consisting of hard cylindrical segments by the Monte-Carlo method including reflection at trivalent vertices.
Denolf, J.M.
2014-01-01
Critical success factors for implementing supply chain information systems – Janne M. Denolf Due to intensified competition, companies realize that they should closely collaborate with their supply-chain partners to further cut costs and stay competitive. To do so, supply-chain partners should intensify information sharing, which is often facilitated through supply chain information systems (SCIS). Implementation of such a system is a complex undertaking due to the umpteen technical and organ...
Residue-Specific Side-Chain Polymorphisms via Particle Belief Propagation.
Ghoraie, Laleh Soltan; Burkowski, Forbes; Li, Shuai Cheng; Zhu, Mu
2014-01-01
Protein side chains populate diverse conformational ensembles in crystals. Despite much evidence that there is widespread conformational polymorphism in protein side chains, most of the X-ray crystallography data are modeled by single conformations in the Protein Data Bank. The ability to extract or to predict these conformational polymorphisms is of crucial importance, as it facilitates deeper understanding of protein dynamics and functionality. In this paper, we describe a computational strategy capable of predicting side-chain polymorphisms. Our approach extends a particular class of algorithms for side-chain prediction by modeling the side-chain dihedral angles more appropriately as continuous rather than discrete variables. Employing a new inferential technique known as particle belief propagation, we predict residue-specific distributions that encode information about side-chain polymorphisms. Our predicted polymorphisms are in relatively close agreement with results from a state-of-the-art approach based on X-ray crystallography data, which characterizes the conformational polymorphisms of side chains using electron density information, and has successfully discovered previously unmodeled conformations.
Supply Chain Management in Industrial Symbiosis Networks
DEFF Research Database (Denmark)
Herczeg, Gabor
2016-01-01
, as well as in policy documents from e.g. the European Union, the concepts of circular econ- omy and closed-loop supply chains have received significant attention. One of the manifestations of these developments are industrial symbiosis networks. These networks are a collaborative effort to more...... sustainable production op- erations, and are characterized by a supply chain reconfiguration that uses one company’s wastes or by-products as a raw material for another company, avoiding waste disposal while also reducing material requirements. The re- sulting networks of relationships contribute to regional...... sustainable develop- ment efforts, and emphasize synergistic relations, community, and collabora- tion. This thesis takes an operations and supply chain management perspec- tive on industrial symbiosis networks. More specifically, the thesis elaborates on the collaborative and competitive characteristics...
On a Markov chain roulette-type game
International Nuclear Information System (INIS)
El-Shehawey, M A; El-Shreef, Gh A
2009-01-01
A Markov chain on non-negative integers which arises in a roulette-type game is discussed. The transition probabilities are p 01 = ρ, p Nj = δ Nj , p i,i+W = q, p i,i-1 = p = 1 - q, 1 ≤ W < N, 0 ≤ ρ ≤ 1, N - W < j ≤ N and i = 1, 2, ..., N - W. Using formulae for the determinant of a partitioned matrix, a closed form expression for the solution of the Markov chain roulette-type game is deduced. The present analysis is supported by two mathematical models from tumor growth and war with bargaining
Lee, Dong-Rour; Kim, Laurentius Jongsoon
2016-08-01
Many studies have explored closed kinetic chain (CKC) shoulder exercises (SEs) with a sling because they are safer and more effective than open-chain exercises, especially in early stages of treatment. However, the application of CKC SE in youth baseball players has rarely been attempted, although teenage baseball players also experience shoulder pain. To investigate the effects of CKC SE on the peak torque of shoulder internal rotation (IR) and external rotation (ER) in youth baseball players. Single-group pretest, posttest. Biomechanics laboratory. 23 Little League Baseball players with subacromial impingement syndrome. The CKC SE with a sling was CKC shoulder-flexion exercise, extension exercise, IR exercise, and ER exercise. This exercise regimen was conducted 2 or 3 times/wk for 8 wk. The peak torque of shoulder IR and ER was measured using an isokinetic dynamometer. Concentric shoulder rotation was performed, with 5 repetitions at an angular velocity of 60°/s and 15 at 180°/s. The IR and ER peak torque significantly increased at each angular velocity after the exercise program. In particular, the increase in IR and ER peak torque values was statistically significant at an angular velocity of 180°/s. CKC SE was effective in increasing shoulder IR and ER strength, demonstrating its potential benefits in the prevention and treatment of shoulder injury. In addition, increased IR peak torque appears to improve throwing velocity in baseball players.
Integrable open spin chains and the doubling trick in N = 2 SYM with fundamental matter
International Nuclear Information System (INIS)
Erler, Theodore G.; Mann, Nelia
2006-01-01
We demonstrate that the one-loop anomalous dimension matrix in N = 2 SYM with a single chiral hypermultiplet of fundamental matter, which is dual to AdS 5 x S 5 with a D7-brane filling AdS 5 and wrapped around an S 3 in the S 5 , is an integrable open spin chain Hamiltonian. We also use the doubling trick to relate these open spin chains to closed spin chains in pure N = 4 SYM. By using the AdS/CFT correspondence, we find a relation between the corresponding open and closed strings that differs from a simple doubling trick by terms that vanish in the semiclassical limit. We also demonstrate that in some cases the closed string is simpler and easier to study than the corresponding open string, and we speculate on the nature of corrections due to the presence of D-branes that this implies
Masses of nuclei close to the dripline
International Nuclear Information System (INIS)
Herfurth, F.; Blaum, K.; Audi, G.; Lunney, D.; Beck, D.; Kluge, H.J.; Rodriguez, D.; Sikler, G.; Weber, C.; Bollen, G.; Schwarz, S.; Kellerbauer, A.
2003-01-01
Mass measurements of radioactive nuclides are one of the cornerstones of our understanding of the nucleus. The Penning trap spectrometer ISOLTRAP performs direct mass measurements far away from the valley of stability, as well as high-precision measurements of key nuclei to anchor long decay chains. Both schemes provide valuable information on the dripline itself and on nuclei in its close vicinity. (orig.)
Cooperation Between Suppliers and Retail Chains in Developing Systemic Products
Directory of Open Access Journals (Sweden)
Katarzyna Bilińska-Reformat
2016-01-01
Full Text Available Seeking a competitive advantage, retail chains develop systemic products. Introducing systemic products to retailers' offer requires establishment of close cooperation with their suppliers. In the paper the assumption has been made that offering systemic products makes the offer more attractive for customer. It is also reason for development of cooperation between retail chains and suppliers. Selected commercial enterprises were research objects in the study. Analyses included in the paper concern the years between 2009 and 2015. Research methods: critical analysis of the literature, results of own research method concerning cooperation between retail chains and suppliers, and the case research method.
Skvortsov, A M; Leermakers, F A M; Fleer, G J
2013-08-07
In the melt polymer conformations are nearly ideal according to Flory's ideality hypothesis. Silberberg generalized this statement for chains in the interfacial region. We check the Silberberg argument by analyzing the conformations of a probe chain end-grafted at a solid surface in a sea of floating free chains of concentration φ by the self-consistent field (SCF) method. Apart from the grafting, probe chain and floating chains are identical. Most of the results were obtained for a standard SCF model with freely jointed chains on a six-choice lattice, where immediate step reversals are allowed. A few data were generated for a five-choice lattice, where such step reversals are forbidden. These coarse-grained models describe the equilibrium properties of flexible atactic polymer chains at the scale of the segment length. The concentration was varied over the whole range from φ = 0 (single grafted chain) to φ = 1 (probe chain in the melt). The number of contacts with the surface, average height of the free end and its dispersion, average loop and train length, tail size distribution, end-point and overall segment distributions were calculated for a grafted probe chain as a function of φ, for several chain lengths and substrate∕polymer interactions, which were varied from strong repulsion to strong adsorption. The computations show that the conformations of the probe chain in the melt do not depend on substrate∕polymer interactions and are very similar to the conformations of a single end-grafted chain under critical conditions, and can thus be described analytically. When the substrate∕polymer interaction is fixed at the value corresponding to critical conditions, all equilibrium properties of a probe chain are independent of φ, over the whole range from a dilute solution to the melt. We believe that the conformations of all flexible chains in the surface region of the melt are close to those of an appropriate single chain in critical conditions, provided
Force decay of elastomeric chains - a mechanical design and product comparison study.
Balhoff, David A; Shuldberg, Matthew; Hagan, Joseph L; Ballard, Richard W; Armbruster, Paul C
2011-03-01
To evaluate the percentage force decay of elastomeric chain products utilizing three different design mechanisms simulating canine retraction; and to evaluate the percentage force decay of elastomeric chain products from four different companies. In vitro, laboratory study. LSUHSC Dental School, New Orleans, LA, USA. Closed (non-spaced), grey elastomeric chains from four companies were selected for the study. Three acrylic resin jigs were constructed to provide a framework for three simulated space closure mechanisms. The 6-5-3, the chain loop, and the 6-3 were the configuration mechanisms used in the study. An electronic force gauge was used to measure the percentage force decay associated with each elastomeric chain over 28 days at preselected times. There was a significant difference in the mean percentage force decay for the three different mechanisms (P < 0·001). For all four companies, the 6-3 mechanical design had the smallest mean percentage force decay. There was a significant difference in the mean percentage force decay for the different companies (P < 0·001). For all three mechanisms, Ormco had the smallest percentage force decay while Unitek had the highest percentage force decay. The significant difference in the mean percentage force decay for the different mechanisms suggests that the 6-3 design is a more efficient means of closing extraction spaces utilizing elastomeric chains.
The How and Why of Interactive Markov Chains
Hermanns, H.; Katoen, Joost P.; de Boer, F.S; Bonsangue, S.H.; Leuschel, M
2010-01-01
This paper reviews the model of interactive Markov chains (IMCs, for short), an extension of labelled transition systems with exponentially delayed transitions. We show that IMCs are closed under parallel composition and hiding, and show how IMCs can be compositionally aggregated prior to analysis
On the magnetostatics of chains of magnetic nanoparticles
DEFF Research Database (Denmark)
Phatak, C.; Pokharel, R.; Beleggia, Marco
2011-01-01
A novel approach is presented for the computation of the magnetostatic energy of straight and bent chains of identical, uniformly magnetized particles of arbitrary shape. The formalism relies on the concept of the magnetometric tensor field, and allows for closed form expressions for the magnetos...
Applying Revenue Management to the Reverse Supply Chain
M. Ferguson (Mark); M. Fleischmann (Moritz); G.C. Souza (Gilvan)
2008-01-01
textabstractWe study the disposition decision for product returns in a closed-loop supply chain. Motivated by the asset recovery process at IBM, we consider two disposition alternatives. Returns may be either refurbished for reselling or dismantled for spare parts. Reselling a refurbished unit
Probability distributions for Markov chain based quantum walks
Balu, Radhakrishnan; Liu, Chaobin; Venegas-Andraca, Salvador E.
2018-01-01
We analyze the probability distributions of the quantum walks induced from Markov chains by Szegedy (2004). The first part of this paper is devoted to the quantum walks induced from finite state Markov chains. It is shown that the probability distribution on the states of the underlying Markov chain is always convergent in the Cesaro sense. In particular, we deduce that the limiting distribution is uniform if the transition matrix is symmetric. In the case of a non-symmetric Markov chain, we exemplify that the limiting distribution of the quantum walk is not necessarily identical with the stationary distribution of the underlying irreducible Markov chain. The Szegedy scheme can be extended to infinite state Markov chains (random walks). In the second part, we formulate the quantum walk induced from a lazy random walk on the line. We then obtain the weak limit of the quantum walk. It is noted that the current quantum walk appears to spread faster than its counterpart-quantum walk on the line driven by the Grover coin discussed in literature. The paper closes with an outlook on possible future directions.
Denolf, J.M.
2014-01-01
Critical success factors for implementing supply chain information systems – Janne M. Denolf
Due to intensified competition, companies realize that they should closely collaborate with their supply-chain partners to further cut costs and stay competitive. To do so,
Power of Companies in Supply Chains and Their Effect on Network Development
Tamás Brányi; László Józsa
2015-01-01
A general supply chain functions as a closed cluster and consists of at least three companies: supplier, producer and buyer. In an optimal case the companies within a supply chain are well integrated, partnership rests on trust which results in common strategic decisions. Business practices show that there is a stronger company within the chain that uses its power position to influence network development. The objective of the research is to measure how and what kind of power position is need...
Absence of diffusion in disordered spin-chains
Gazit, Snir; Khait, Ilia; Yao, Norman; Auerbach, Assa
We study the dynamical properties of the one dimensional XXZ model at infinite temperature in the presence of quench disorder. This model is expected to exhibit a many body localization (MBL) transition at finite disorder. We compute the local dynamical spin correlation function using a non-perturbative continued fraction expansion. The expansion up to 15th order is sufficient to achieve convergence of our extrapolation scheme. We compare the continued fraction result to the exact diagonalization (ED) on 22 sites. The phase diagram is determined in the disorder-anisotropy plane. Our main finding is the emergence of sub-diffusive transport and absence of a diffusive behavior (ω - 1 / 2 at low frequencies) in the weak disorder regime. The lack of a true diffusive phase contrasts with previous results and expectations obtained from smaller system sizes. In addition, the MBL transition is determined to occur at lower values than those deduced by ED on finite systems. Lastly, the finite frequency-momentum dynamical structure factor is computed and we explore its space-time scaling behavior.
Demand chain management - The evolution
Directory of Open Access Journals (Sweden)
D Ericsson
2011-06-01
Full Text Available The concepts of Supply Chain Management (SCM and Demand Chain Management (DCM are among the new and debated topics concerning logistics in the literature. The question considered in this paper is: “Are these concepts needed or will they just add to the confusion?” Lasting business concepts have always evolved in close interaction between business and academia. Different approaches start out in business and they are then, more or less si- multaneously, aligned, integrated, systemised and structured in academia. In this way a terminology (or language is provided that helps in further diffusion of the concepts. There is a lack of consensus on the definition of the concept of SCM. This may be one of the major reasons for the difficulty in advancing the science and measuring the results of implementation in business. Relationships in SCM span from rather loose coalitions to highly structured virtual network integrations. DCM is a highly organised chain in which the key is mutual interdependence and partnership. The purpose is to create a distinctive competence for the chain as a whole that helps to identify and satisfy customer needs and wishes. The classical research concerning vertical marketing systems is very helpful in systemising the rather unstructured discussions in current SCM research. The trend lies in increasing competition between channels rather than between companies, which in turn leads to the creation of channels with a high degree of partnership and mutual interdependence between members. These types of channels are known as organised vertical marketing systems in the classic marketing channel research. The behaviour in these types of channels, as well as the formal and informal structures, roles in the network, power and dependence relations, etc. are well covered topics in the literature. The concept of vertical marketing systems lies behind the definition of demand chains and demand chain management proposed in this paper. A
Relaxation Dynamics of Nanoparticle-Tethered Polymer Chains
Kim, Sung A
2015-09-08
© 2015 American Chemical Society. Relaxation dynamics of nanoparticle-tethered cis-1,4-polyisoprene (PI) are investigated using dielectric spectroscopy and rheometry. A model system composed of polymer chains densely grafted to spherical SiO2 nanoparticles to form self-suspended suspensions facilitates detailed studies of slow global chain and fast segmental mode dynamics under surface and geometrical confinement-from experiments performed in bulk materials. We report that unentangled polymer molecules tethered to nanoparticles relax far more slowly than their tethered entangled counterparts. Specifically, at fixed grafting density we find, counterintuitively, that increasing the tethered polymer molecular weight up to values close to the entanglement molecular weight speeds up chain relaxation dynamics. Decreasing the polymer grafting density for a fixed molecular weight has the opposite effect: it dramatically slows down chain relaxation, increases interchain coupling, and leads to a transition in rheological response from simple fluid behavior to viscoelastic fluid behavior for tethered PI chains that are unentangled by conventional measures. Increasing the measurement temperature produces an even stronger elastic response and speeds up molecular relaxation at a rate that decreases with grafting density and molecular weight. These observations are discussed in terms of chain confinement driven by crowding between particles and by the existence of an entropic attractive force produced by the space-filling constraint on individual chains in a self-suspended material. Our results indicate that the entropic force between densely grafted polymer molecules couples motions of individual chains in an analogous manner to reversible cross-links in associating polymers.
Indecomposability parameters in chiral logarithmic conformal field theory
International Nuclear Information System (INIS)
Vasseur, Romain; Jacobsen, Jesper Lykke; Saleur, Hubert
2011-01-01
Work of the last few years has shown that the key algebraic features of Logarithmic Conformal Field Theories (LCFTs) are already present in some finite lattice systems (such as the XXZ spin-1/2 chain) before the continuum limit is taken. This has provided a very convenient way to analyze the structure of indecomposable Virasoro modules and to obtain fusion rules for a variety of models such as (boundary) percolation etc. LCFTs allow for additional quantum numbers describing the fine structure of the indecomposable modules, and generalizing the 'b-number' introduced initially by Gurarie for the c=0 case. The determination of these indecomposability parameters (or logarithmic couplings) has given rise to a lot of algebraic work, but their physical meaning has remained somewhat elusive. In a recent paper, a way to measure b for boundary percolation and polymers was proposed. We generalize this work here by devising a general strategy to compute matrix elements of Virasoro generators from the numerical analysis of lattice models and their continuum limit. The method is applied to XXZ spin-1/2 and spin-1 chains with open (free) boundary conditions. They are related to gl(n+m|m) and osp(n+2m|2m)-invariant superspin chains and to non-linear sigma models with supercoset target spaces. These models can also be formulated in terms of dense and dilute loop gas. We check the method in many cases where the results were already known analytically. Furthermore, we also confront our findings with a construction generalizing Gurarie's, where logarithms emerge naturally in operator product expansions to compensate for apparently divergent terms. This argument actually allows us to compute indecomposability parameters in any logarithmic theory. A central result of our study is the construction of a Kac table for the indecomposability parameters of the logarithmic minimal models LM(1,p) and LM(p,p+1).
Spinon confinement in a quasi-one-dimensional XXZ Heisenberg antiferromagnet
Lake, Bella; Bera, Anup K.; Essler, Fabian H. L.; Vanderstraeten, Laurens; Hubig, Claudius; Schollwock, Ulrich; Islam, A. T. M. Nazmul; Schneidewind, Astrid; Quintero-Castro, Diana L.
Half-integer spin Heisenberg chains constitute a key paradigm for quantum number fractionalization: flipping a spin creates a minimum of two elementary spinon excitations. These have been observed in numerous experiments. We report on inelastic neutron scattering experiments on the quasi-one-dimensional anisotropic spin-1/2 Heisenberg antiferromagnet SrCo2V2O8. These reveal a mechanism for temperature-induced spinon confinement, manifesting itself in the formation of sequences of spinon bound states. A theoretical description of this effect is achieved by a combination of analytical and numerical methods.
Newtonian Analysis of a Folded Chain Drop
Mungan, Carl E.
2018-05-01
Consider a chain of length L that hangs in a U shape with end A fixed to a rigid support and free end E released from rest starting from the same initial height (call it y = 0) as A. Figure 1 sketches the chain after end E has fallen a distance y. Points O and A are assumed to be close enough to each other and the chain flexible enough that the radius of curvature r at the bottom point C can be taken to be negligibly small (compared to the length of the chain). The problem is to compare the speed of descent v(y) = dy/dt of the free end E of the chain to the speed vfree(y )=√{2 g y } of a free-falling point mass that has descended the same distance y. If v(y) > vfree (y) for all y > 0, then, in a race to fall any arbitrary distance Y (where 0 < Y < L), the chain end E will always beat a simultaneously released point mass, because the fall time t for E will be shorter than tfree for the point mass, t = ∫0 Y d/y v (y )
Research on the Logistics Supply Chain in Port Logistics Transportation
Wang Yan-liang
2013-01-01
The aim of this study is to improve and increase the logistics system effectiveness and to solve the problem of optimal movement of different flows. Logistics transport carrying the world on material resources transfer exchange important mission and economic development and our lives are closely linked, logistics chain logistics transport occupies an important position and in the e logistics chain in port logistics has play a decisive role. For many coastal countries port logistics is the eco...
Excitation of bond-alternating spin-1/2 Heisenberg chains by tunnelling electrons
International Nuclear Information System (INIS)
Gauyacq, J-P; Lorente, N
2014-01-01
Inelastic electron tunneling spectra (IETS) are evaluated for spin-1/2 Heisenberg chains showing different phases of their spin ordering. The spin ordering is controlled by the value of the two different Heisenberg couplings on the two sides of each of the chain's atoms (bond-alternating chains). The perfect anti-ferromagnetic phase, i.e. a unique exchange coupling, marks a topological quantum phase transition (TQPT) of the bond-alternating chain. Our calculations show that the TQPT is recognizable in the excited states of the chain and hence that IETS is in principle capable of discriminating the phases. We show that perfectly symmetric chains, such as closed rings mimicking infinite chains, yield the same spectra on both sides of the TQPT and IETS cannot reveal the nature of the spin phase. However, for finite size open chains, both sides of the TQPT are associated with different IETS spectra, especially on the edge atoms, thus outlining the transition. (paper)
Magnetization and spin gap in two-dimensional organic ferrimagnet BIPNNBNO
International Nuclear Information System (INIS)
Ovchinnikov, A S; Sinitsyn, V E; Bostrem, I G; Hosokoshi, Y; Inoue, K
2012-01-01
A magnetization process in the two-dimensional ferrimagnet BIPNNBNO is analyzed. The compound consists of ferrimagnetic (1,1/2) chains coupled by two sorts of antiferromagnetic interaction. Whereas the behavior of the magnetization curve in higher magnetic fields can be understood within a process for the separate ferrimagnetic chain, the appearance of the singlet plateau at lower fields is an example of non-Lieb-Mattis type ferrimagnetism. By using the exact diagonalization technique for finite clusters of size 4 × 6, 4 × 8 and 4 × 10 we show that the interchain frustration coupling plays an essential role in stabilization of the singlet phase. These results are complemented by an analysis of four cylindrically coupled ferrimagnetic (1,1/2) chains via an Abelian bosonization technique and an effective theory based on the XXZ spin-1/2 Heisenberg model when the interchain interactions are sufficiently weak/strong, respectively. (paper)
Random close packing in protein cores
Gaines, Jennifer C.; Smith, W. Wendell; Regan, Lynne; O'Hern, Corey S.
2015-01-01
Shortly after the determination of the first protein x-ray crystal structures, researchers analyzed their cores and reported packing fractions $\\phi \\approx 0.75$, a value that is similar to close packing equal-sized spheres. A limitation of these analyses was the use of `extended atom' models, rather than the more physically accurate `explicit hydrogen' model. The validity of using the explicit hydrogen model is proved by its ability to predict the side chain dihedral angle distributions obs...
Directory of Open Access Journals (Sweden)
Wenbin Wang
2018-06-01
Full Text Available We investigate a closed-loop supply chain (CLSC where the retailer and the third-party recycler compete against each other to collect waste electrical and electronic equipment (WEEE given that collection effort is their private information. Using the principle-agent theory, we develop a CLSC model with dual collection channel without the government’s reward–penalty mechanism (RPM. An information screening contract is designed for the manufacturer to attain real information on collection effort levels; meanwhile, the optimal decision-making results of other decision variables are derived. Next, we take RPM into account to further examine the efficacy of the government’s guidance mechanism in improving collection rate and profits of CLSC members. Our results indicate that (i the collection competition reduces the total collection quantity and the expected profits of all the CLSC members without RPM; (ii all CLSC members’ expected profits are improved if both two collection agents select a high collection effort level without and with RPM; (iii RPM increases buyback price, collection price, collection quantity, and franchise fee but decreases wholesale price and retail price; with the reward–penalty intensity increasing, the manufacturer’s expected profit first decreases and then increases, while the expected profits of H-type retailer and H-type third-party recycler continue to increase. We find that RPM may ultimately stimulate the collection agents to collect more WEEEs, while the intense collection competition reduces the profits of CLSC members.
Fragmentation kinetics of a Morse oscillator chain under tension
International Nuclear Information System (INIS)
Stember, Joseph N.; Ezra, Gregory S.
2007-01-01
The bond dissociation kinetics of tethered atomic (Morse potential) chains under tensile stress is studied. Both RRKM (fully anharmonic, Monte Carlo) and RRK (harmonic appproximation) theory are applied to predict bond dissociation rate constants as a function of energy and tensile force. For chains with N ≥ 3 atoms a hybrid statistical theory is used involving a harmonic approximation for motion in the transition state for bond dissociation. For chains with N = 2-5 atoms, while the RRK approximation significantly overestimates the dissociation rate constant, the fully anharmonic RRKM rate is quite close to simulation results. For the N = 2 chain, a novel approach to the extraction of decay rate constants based on the classical spectral theorem is implemented. Good agreement between the RRKM and dynamical rate constants is obtained for N = 2 despite the fact that the reactant phase space contains a significant fraction of relatively short-lived trajectories
Decentralization Policies for Supply Chain Investments under Asymmetric Information
DEFF Research Database (Denmark)
Agrell, Per Joakim; Bogetoft, Peter
2017-01-01
Supply chains need specific investments for improved performance in terms of lead-time, cost, and quality. We study the contractual choice of a coordinator to either centralize or delegate the investment decision in a three-stage chain. The analysis derives closed-form results for the economic...... performance of three decentralized contracting schemes under asymmetric information on investment cost, as well as the optimal full revelation results. The results show that the observed practice of tier-1 delegated investments leads to relatively poor performance because of underinvestment. We illustrate...
Perception as a closed-loop convergence process.
Ahissar, Ehud; Assa, Eldad
2016-05-09
Perception of external objects involves sensory acquisition via the relevant sensory organs. A widely-accepted assumption is that the sensory organ is the first station in a serial chain of processing circuits leading to an internal circuit in which a percept emerges. This open-loop scheme, in which the interaction between the sensory organ and the environment is not affected by its concurrent downstream neuronal processing, is strongly challenged by behavioral and anatomical data. We present here a hypothesis in which the perception of external objects is a closed-loop dynamical process encompassing loops that integrate the organism and its environment and converging towards organism-environment steady-states. We discuss the consistency of closed-loop perception (CLP) with empirical data and show that it can be synthesized in a robotic setup. Testable predictions are proposed for empirical distinction between open and closed loop schemes of perception.
Kinetic chains: a review of the concept and its clinical applications.
Karandikar, Ninad; Vargas, Oscar O Ortiz
2011-08-01
During the past decade, our understanding of biomechanics and its importance in rehabilitation has advanced significantly. The kinetic chain, a concept borrowed from engineering, has helped us better understand the underlying physiology of human movement. This understanding, in turn, has facilitated the development of new and more rational rehabilitation strategies. The kinetic chain concept has application in a wide spectrum of clinical conditions, including musculoskeletal medicine, sports medicine, and neurorehabilitation, as well as prosthetics and orthotics. The purpose of this review is to provide insights into the biomechanics related to the concept of kinetic chains, with a specific focus on closed kinetic chains and its clinical applications in rehabilitation. Copyright © 2011 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.
Excitonic quantum interference in a quantum dot chain with rings.
Hong, Suc-Kyoung; Nam, Seog Woo; Yeon, Kyu-Hwang
2008-04-16
We demonstrate excitonic quantum interference in a closely spaced quantum dot chain with nanorings. In the resonant dipole-dipole interaction model with direct diagonalization method, we have found a peculiar feature that the excitation of specified quantum dots in the chain is completely inhibited, depending on the orientational configuration of the transition dipole moments and specified initial preparation of the excitation. In practice, these excited states facilitating quantum interference can provide a conceptual basis for quantum interference devices of excitonic hopping.
Superconducting, magnetic, and charge correlations in the doped two-chain Hubbard model
International Nuclear Information System (INIS)
Asai, Y.
1995-01-01
We have studied the superconducting, magnetic, and charge correlation functions and the spin excitation spectrum in the doped two-chain Hubbard model by projector Monte Carlo and Lanczos diagonalization methods. The exponent of the interchain singlet superconducting correlation function, γ, is found to be close to 2.0 as long as two distinct noninteracting bands cross the Fermi level. Magnetic and charge correlation functions decay more rapidly than or as fast as the interchain singlet superconducting correlation function along the chains. The superconducting correlation in the doped two-chain Hubbard model is the most long-range correlation studied here. Implications of the results for the possible universality class of the doped two-chain Hubbard model are discussed
Local conservation laws and the structure of the many-body localized states.
Serbyn, Maksym; Papić, Z; Abanin, Dmitry A
2013-09-20
We construct a complete set of local integrals of motion that characterize the many-body localized (MBL) phase. Our approach relies on the assumption that local perturbations act locally on the eigenstates in the MBL phase, which is supported by numerical simulations of the random-field XXZ spin chain. We describe the structure of the eigenstates in the MBL phase and discuss the implications of local conservation laws for its nonequilibrium quantum dynamics. We argue that the many-body localization can be used to protect coherence in the system by suppressing relaxation between eigenstates with different local integrals of motion.
Variational model for one-dimensional quantum magnets
Kudasov, Yu. B.; Kozabaranov, R. V.
2018-04-01
A new variational technique for investigation of the ground state and correlation functions in 1D quantum magnets is proposed. A spin Hamiltonian is reduced to a fermionic representation by the Jordan-Wigner transformation. The ground state is described by a new non-local trial wave function, and the total energy is calculated in an analytic form as a function of two variational parameters. This approach is demonstrated with an example of the XXZ-chain of spin-1/2 under a staggered magnetic field. Generalizations and applications of the variational technique for low-dimensional magnetic systems are discussed.
A note on a boundary sine-Gordon model at the free-Fermion point
Murgan, Rajan
2018-02-01
We investigate the free-Fermion point of a boundary sine-Gordon model with nondiagonal boundary interactions for the ground state using auxiliary functions obtained from T - Q equations of a corresponding inhomogeneous open spin-\\frac{1}{2} XXZ chain with nondiagonal boundary terms. In particular, we obtain the Casimir energy. Our result for the Casimir energy is shown to agree with the result from the TBA approach. The analytical result for the effective central charge in the ultraviolet (UV) limit is also verified from the plots of effective central charge for intermediate values of volume.
Coupled motions direct electrons along human microsomal P450 Chains.
Directory of Open Access Journals (Sweden)
Christopher R Pudney
2011-12-01
Full Text Available Protein domain motion is often implicated in biological electron transfer, but the general significance of motion is not clear. Motion has been implicated in the transfer of electrons from human cytochrome P450 reductase (CPR to all microsomal cytochrome P450s (CYPs. Our hypothesis is that tight coupling of motion with enzyme chemistry can signal "ready and waiting" states for electron transfer from CPR to downstream CYPs and support vectorial electron transfer across complex redox chains. We developed a novel approach to study the time-dependence of dynamical change during catalysis that reports on the changing conformational states of CPR. FRET was linked to stopped-flow studies of electron transfer in CPR that contains donor-acceptor fluorophores on the enzyme surface. Open and closed states of CPR were correlated with key steps in the catalytic cycle which demonstrated how redox chemistry and NADPH binding drive successive opening and closing of the enzyme. Specifically, we provide evidence that reduction of the flavin moieties in CPR induces CPR opening, whereas ligand binding induces CPR closing. A dynamic reaction cycle was created in which CPR optimizes internal electron transfer between flavin cofactors by adopting closed states and signals "ready and waiting" conformations to partner CYP enzymes by adopting more open states. This complex, temporal control of enzyme motion is used to catalyze directional electron transfer from NADPH→FAD→FMN→heme, thereby facilitating all microsomal P450-catalysed reactions. Motions critical to the broader biological functions of CPR are tightly coupled to enzyme chemistry in the human NADPH-CPR-CYP redox chain. That redox chemistry alone is sufficient to drive functionally necessary, large-scale conformational change is remarkable. Rather than relying on stochastic conformational sampling, our study highlights a need for tight coupling of motion to enzyme chemistry to give vectorial electron
AN EXPLORATORY APPROACH TO INTEGRATION OF BUSINESS PRACTICES IN SUPPLY CHAIN MANAGEMENT
Constangioara Alexandru
2014-01-01
Literature on supply chain management focuses increasingly on the topic of supply chain integration. Morash and Bowersox (1989) show that integration links relationships, activities, functions, processes and locations. Integration links a firm with its customers, suppliers and other channel members. The empirical research brings supporting evidence on the theory that organizations achieve the desired competitive advantage only by focusing on one strategy – either collaborative closeness or op...
Smith-Purcell radiation from a chain of spheres
International Nuclear Information System (INIS)
Lekomtsev, K V; Strikhanov, M N; Tishchenko, A A
2010-01-01
Smith-Purcell and diffraction radiation were investigated. These types of radiation appear when a charged particle moves close to a conducting target. Spectral and angular distribution of diffraction radiation from the non-periodic chain of spheres is obtained analytically; local field effects are discussed. Analytical expression for the distribution of Smith-Purcell radiation from the periodic chain of spheres is obtained as well. For the first time it has been shown, that Smith-Purcell radiation for such a system is distributed over the cone. The results are investigated for the particles of different sizes, dielectric and metal, and for both ultrarelativistic and nonrelativistic cases.
A birth-death process suggested by a chain sequence
Lenin, R.B.; Parthasarathy, P.R.
2000-01-01
We consider a birth-death process whose birth and death rates are suggested by a chain sequence. We use an elegant transformation to find the transition probabilities in a simple closed form. We also find an explicit expression for time-dependent mean. We find parallel results in discrete time.
Ion beam focusing by the atomic chains of a crystal lattice
International Nuclear Information System (INIS)
Shulga, V.I.
1975-01-01
A study is made of the focusing of a parallel ion beam by a pair of close packed atomic chains of a crystal. The focal length of this system has been calculated to the approximation of continuous potential of chain in the general form and also for a number of specific potentials of ion-atom interactions. Ar ion beam focusing by a Cu chain pair is discusssed in detail. For this case, the focal length has been calculated as a function of ion energy using the method of computer simulation of ion trajectories in the chain field. The calculations were made on the basis of the Born-Mayer potential with various constants. A pronounced dependence of focal length on the constant in this potential has been found. (author)
Power-law creep behavior of a semiflexible chain.
Majumdar, Arnab; Suki, Béla; Rosenblatt, Noah; Alencar, Adriano M; Stamenović, Dimitrije
2008-10-01
Rheological properties of adherent cells are essential for their physiological functions, and microrheological measurements on living cells have shown that their viscoelastic responses follow a weak power law over a wide range of time scales. This power law is also influenced by mechanical prestress borne by the cytoskeleton, suggesting that cytoskeletal prestress determines the cell's viscoelasticity, but the biophysical origins of this behavior are largely unknown. We have recently developed a stochastic two-dimensional model of an elastically joined chain that links the power-law rheology to the prestress. Here we use a similar approach to study the creep response of a prestressed three-dimensional elastically jointed chain as a viscoelastic model of semiflexible polymers that comprise the prestressed cytoskeletal lattice. Using a Monte Carlo based algorithm, we show that numerical simulations of the chain's creep behavior closely correspond to the behavior observed experimentally in living cells. The power-law creep behavior results from a finite-speed propagation of free energy from the chain's end points toward the center of the chain in response to an externally applied stretching force. The property that links the power law to the prestress is the chain's stiffening with increasing prestress, which originates from entropic and enthalpic contributions. These results indicate that the essential features of cellular rheology can be explained by the viscoelastic behaviors of individual semiflexible polymers of the cytoskeleton.
CHAINS-PC, Decay Chain Atomic Densities
International Nuclear Information System (INIS)
1994-01-01
1 - Description of program or function: CHAINS computes the atom density of members of a single radioactive decay chain. The linearity of the Bateman equations allows tracing of interconnecting chains by manually accumulating results from separate calculations of single chains. Re-entrant loops can be treated as extensions of a single chain. Losses from the chain are also tallied. 2 - Method of solution: The Bateman equations are solved analytically using double-precision arithmetic. Poles are avoided by small alterations of the loss terms. Multigroup fluxes, cross sections, and self-shielding factors entered as input are used to compute the effective specific reaction rates. The atom densities are computed at any specified times. 3 - Restrictions on the complexity of the problem: Maxima of 100 energy groups, 100 time values, 50 members in a chain
International Nuclear Information System (INIS)
Aziziankohan, A.; Jolai, F.; Khalilzadeh, M.; Soltani, R.; Tavakkoli-Moghaddam, R.
2017-01-01
Purpose: Nowadays, governments and people pay more attention to use green products due to environmental pollution, irreplaceable energy and shortage of resources. Green products are resulted from the application of green supply chain management strategies to the organizations' performance strategies, so that we can reduce environmental pollutants and wastes and take a step towards saving energy with limited resources. Methodology: In this paper, the effect of reducing energy consumption in green supply chain is examined by using queuing theory and transportation models. Data was generated and solved by a commercial optimization epackage. Findings: The findings indicate that suitable assignment of existing transportation fleet with specified capacity, and using queueing theory in a closed-loop network to reduce the queue length and handle congestion, can cause a reduction in energy consumption by optimizing transportation and waiting times in a green supply chain. Originality/value: Adopting investment strategy in improving the environmental performance of the supply chain, will yield in many advantages and benefits. This article investigates the effect of queuing theory on reducing waiting time, optimizing energy consumption in green supply chain, and consequently decreasing pollution.
Directory of Open Access Journals (Sweden)
Arvin Aziziankohan
2017-05-01
Full Text Available Purpose: Nowadays, governments and people pay more attention to use green products due to environmental pollution, irreplaceable energy and shortage of resources. Green products are resulted from the application of green supply chain management strategies to the organizations' performance strategies, so that we can reduce environmental pollutants and wastes and take a step towards saving energy with limited resources. Methodology: In this paper, the effect of reducing energy consumption in green supply chain is examined by using queuing theory and transportation models. Data was generated and solved by a commercial optimization epackage. Findings: The findings indicate that suitable assignment of existing transportation fleet with specified capacity, and using queueing theory in a closed-loop network to reduce the queue length and handle congestion, can cause a reduction in energy consumption by optimizing transportation and waiting times in a green supply chain. Originality/value: Adopting investment strategy in improving the environmental performance of the supply chain, will yield in many advantages and benefits. This article investigates the effect of queuing theory on reducing waiting time, optimizing energy consumption in green supply chain, and consequently decreasing pollution.
Energy Technology Data Exchange (ETDEWEB)
Aziziankohan, A.; Jolai, F.; Khalilzadeh, M.; Soltani, R.; Tavakkoli-Moghaddam, R.
2017-07-01
Purpose: Nowadays, governments and people pay more attention to use green products due to environmental pollution, irreplaceable energy and shortage of resources. Green products are resulted from the application of green supply chain management strategies to the organizations' performance strategies, so that we can reduce environmental pollutants and wastes and take a step towards saving energy with limited resources. Methodology: In this paper, the effect of reducing energy consumption in green supply chain is examined by using queuing theory and transportation models. Data was generated and solved by a commercial optimization epackage. Findings: The findings indicate that suitable assignment of existing transportation fleet with specified capacity, and using queueing theory in a closed-loop network to reduce the queue length and handle congestion, can cause a reduction in energy consumption by optimizing transportation and waiting times in a green supply chain. Originality/value: Adopting investment strategy in improving the environmental performance of the supply chain, will yield in many advantages and benefits. This article investigates the effect of queuing theory on reducing waiting time, optimizing energy consumption in green supply chain, and consequently decreasing pollution.
Bethe Ansatz and supersymmetric vacua
International Nuclear Information System (INIS)
Nekrasov, Nikita; Shatashvili, Samson
2009-01-01
Supersymmetric vacua of two dimensional N = 4 gauge theories with matter, softly broken by the twisted masses down to N = 2, are shown to be in one-to-one correspondence with the eigenstates of integrable spin chain Hamiltonians. Examples include: the Heisenberg SU(2)XXX spin chain which is mapped to the two dimensional U(N) theory with fundamental hypermultiplets, the XXZ spin chain which is mapped to the analogous three dimensional super-Yang-Mills theory compactified on a circle, the XYZ spin chain and eight-vertex model which are related to the four dimensional theory compactified on T 2 . A consequence of our correspondence is the isomorphism of the quantum cohomology ring of various quiver varieties, such as cotangent bundles to (partial) flag varieties and the ring of quantum integrals of motion of various spin chains. The correspondence extends to any spin group, representations, boundary conditions, and inhomogeneity, it includes Sinh-Gordon and non-linear Schroedinger models as well as the dynamical spin chains like Hubbard model. Compactifications of four dimensional N = 2 theories on a two-sphere lead to the instanton-corrected Bethe equations.
Xing, Yuanzhi; Deng, Xiaoyi
2017-11-01
The paper first has defined the concepts of green supply chain management and evolution game theory, and pointed out the characteristics of green supply chain management in construction. The main participants and key links of the construction green supply chain management are determined by constructing the organization framework. This paper established the evolutionary game model between construction enterprises and recycling enterprises for the green supply chain closed-loop structure. The waste recycling evolutionary stability equilibrium solution is obtained to explore the principle and effective scope of government policy intervention. This paper put forward the relevant countermeasures to the green supply chain management in construction recycling stage from the government point of view. The conclusion has reference value and guidance to the final product construction enterprises, recycling enterprises and the government during green supply chain.
Random close packing in protein cores.
Gaines, Jennifer C; Smith, W Wendell; Regan, Lynne; O'Hern, Corey S
2016-03-01
Shortly after the determination of the first protein x-ray crystal structures, researchers analyzed their cores and reported packing fractions ϕ ≈ 0.75, a value that is similar to close packing of equal-sized spheres. A limitation of these analyses was the use of extended atom models, rather than the more physically accurate explicit hydrogen model. The validity of the explicit hydrogen model was proved in our previous studies by its ability to predict the side chain dihedral angle distributions observed in proteins. In contrast, the extended atom model is not able to recapitulate the side chain dihedral angle distributions, and gives rise to large atomic clashes at side chain dihedral angle combinations that are highly probable in protein crystal structures. Here, we employ the explicit hydrogen model to calculate the packing fraction of the cores of over 200 high-resolution protein structures. We find that these protein cores have ϕ ≈ 0.56, which is similar to results obtained from simulations of random packings of individual amino acids. This result provides a deeper understanding of the physical basis of protein structure that will enable predictions of the effects of amino acid mutations to protein cores and interfaces of known structure.
Formation of Close-in Super-Earths in an Evolving Disk Due to Disk Winds
Ogihara, Masahiro; Kokubo, Eiichiro; Suzuki, Takeru; Morbidelli, Alessandro
2018-04-01
Planets with masses larger than Mars mass undergo rapid inward migration (type I migration) in a standard protoplanetary disk. Recent magnetohydrodynamical simulations revealed the presence of magnetically-driven disk winds, which would alter the disk profile and the type I migration in the close-in region (rEarths can be reproduced by simulations. We find that the type I migration is significantly suppressed in a disk with flat surface density profile. After planetary embryos undergo slow inward migration, they are captured in a resonant chain. The resonant chain undergoes late orbital instability during the gas depletion, leading to a non-resonant configuration. We also find that observed distributions of close-in super-Earths (e.g., period ratio, mass ratio) can be reproduced by results of simulations.
Exact solution and thermodynamics of a spin chain with long-range elliptic interactions
International Nuclear Information System (INIS)
Finkel, Federico; González-López, Artemio
2014-01-01
We solve in closed form the simplest (su(1|1)) supersymmetric version of Inozemtsev's elliptic spin chain, as well as its infinite (hyperbolic) counterpart. The solution relies on the equivalence of these models to a system of free spinless fermions and on the exact computation of the Fourier transform of the resulting elliptic hopping amplitude. We also compute the thermodynamic functions of the finite (elliptic) chain and their low temperature limit and show that the energy levels become normally distributed in the thermodynamic limit. Our results indicate that at low temperatures the su(1|1) elliptic chain behaves as a critical XX model and deviates in an essential way from the Haldane–Shastry chain. (paper)
Lee, Bruce Y; Connor, Diana L; Wateska, Angela R; Norman, Bryan A; Rajgopal, Jayant; Cakouros, Brigid E; Chen, Sheng-I; Claypool, Erin G; Haidari, Leila A; Karir, Veena; Leonard, Jim; Mueller, Leslie E; Paul, Proma; Schmitz, Michelle M; Welling, Joel S; Weng, Yu-Ting; Brown, Shawn T
2015-08-26
Many of the world's vaccine supply chains do not adequately provide vaccines, prompting several questions: how are vaccine supply chains currently structured, are these structures closely tailored to individual countries, and should these supply chains be radically redesigned? We segmented the 57 GAVI-eligible countries' vaccine supply chains based on their structure/morphology, analyzed whether these segments correlated with differences in country characteristics, and then utilized HERMES to develop a detailed simulation model of three sample countries' supply chains and explore the cost and impact of various alternative structures. The majority of supply chains (34 of 57) consist of four levels, despite serving a wide diversity of geographical areas and population sizes. These four-level supply chains loosely fall into three clusters [(1) 18 countries relatively more bottom-heavy, i.e., many more storage locations lower in the supply chain, (2) seven with relatively more storage locations in both top and lower levels, and (3) nine comparatively more top-heavy] which do not correlate closely with any of the country characteristics considered. For all three cluster types, our HERMES modeling found that simplified systems (a central location shipping directly to immunization locations with a limited number of Hubs in between) resulted in lower operating costs. A standard four-tier design template may have been followed for most countries and raises the possibility that simpler and more tailored designs may be warranted. Copyright © 2015 Elsevier Ltd. All rights reserved.
Research on the leverage effect of the retail chains in China
Directory of Open Access Journals (Sweden)
Xuejun Zhang
2017-03-01
Full Text Available With the development of market economy in China and the rising incomes of people, the level of consumption is continuously upgrading. Meanwhile, the chain retailing industry which is closely linked to people’s daily life is developing rapidly. All these factors lead to the transformation of economic structure of China. Since the foreign retail enterprises, like Walmart, Carrefour, and Metro, entering into China, the local chain retailing industry in China is facing more severe pressure due to the competition. In this situation, this paper will compare and analyze the differences between local retail chains and foreign retailing enterprises using the financial and operating leverage indicators. This paper will also put forward some feasible suggestions.
Heat conduction in diatomic chains with correlated disorder
Savin, Alexander V.; Zolotarevskiy, Vadim; Gendelman, Oleg V.
2017-01-01
The paper considers heat transport in diatomic one-dimensional lattices, containing equal amounts of particles with different masses. Ordering of the particles in the chain is governed by single correlation parameter - the probability for two neighboring particles to have the same mass. As this parameter grows from zero to unity, the structure of the chain varies from regular staggering chain to completely random configuration, and then - to very long clusters of particles with equal masses. Therefore, this correlation parameter allows a control of typical cluster size in the chain. In order to explore different regimes of the heat transport, two interatomic potentials are considered. The first one is an infinite potential wall, corresponding to instantaneous elastic collisions between the neighboring particles. In homogeneous chains such interaction leads to an anomalous heat transport. The other one is classical Lennard-Jones interatomic potential, which leads to a normal heat transport. The simulations demonstrate that the correlated disorder of the particle arrangement does not change the convergence properties of the heat conduction coefficient, but essentially modifies its value. For the collision potential, one observes essential growth of the coefficient for fixed chain length as the limit of large homogeneous clusters is approached. The thermal transport in these models remains superdiffusive. In the Lennard-Jones chain the effect of correlation appears to be not monotonous in the limit of low temperatures. This behavior stems from the competition between formation of long clusters mentioned above, and Anderson localization close to the staggering ordered state.
Heat conduction in diatomic chains with correlated disorder
Energy Technology Data Exchange (ETDEWEB)
Savin, Alexander V., E-mail: asavin@center.chph.ras.ru [Semenov Institute of Chemical Physics, Russian Academy of Sciences, 4 Kosygin str., 119991 Moscow (Russian Federation); Zolotarevskiy, Vadim; Gendelman, Oleg V. [Faculty of Mechanical Engineering, Technion – Israel Institute of Technology, Haifa 32000 (Israel)
2017-01-23
The paper considers heat transport in diatomic one-dimensional lattices, containing equal amounts of particles with different masses. Ordering of the particles in the chain is governed by single correlation parameter – the probability for two neighboring particles to have the same mass. As this parameter grows from zero to unity, the structure of the chain varies from regular staggering chain to completely random configuration, and then – to very long clusters of particles with equal masses. Therefore, this correlation parameter allows a control of typical cluster size in the chain. In order to explore different regimes of the heat transport, two interatomic potentials are considered. The first one is an infinite potential wall, corresponding to instantaneous elastic collisions between the neighboring particles. In homogeneous chains such interaction leads to an anomalous heat transport. The other one is classical Lennard–Jones interatomic potential, which leads to a normal heat transport. The simulations demonstrate that the correlated disorder of the particle arrangement does not change the convergence properties of the heat conduction coefficient, but essentially modifies its value. For the collision potential, one observes essential growth of the coefficient for fixed chain length as the limit of large homogeneous clusters is approached. The thermal transport in these models remains superdiffusive. In the Lennard–Jones chain the effect of correlation appears to be not monotonous in the limit of low temperatures. This behavior stems from the competition between formation of long clusters mentioned above, and Anderson localization close to the staggering ordered state.
A TBA approach to thermal transport in the XXZ Heisenberg model
Zotos, X.
2017-10-01
We show that the thermal Drude weight and magnetothermal coefficient of the 1D easy-plane Heisenberg model can be evaluated by an extension of the Bethe ansatz thermodynamics formulation by Takahashi and Suzuki (1972 Prog. Theor. Phys. 48 2187). They have earlier been obtained by the quantum transfer matrix method (Klümper 1999 Z. Phys. B 91 507). Furthermore, this approach can be applied to the study of the far-out of equilibrium energy current generated at the interface between two semi-infinite chains held at different temperatures.
Understanding a Value Chain in Health Care.
Sharan, Alok D; Schroeder, Gregory D; West, Michael E; Vaccaro, Alexander R
2015-10-01
As the US health care system transitions toward a value-based system, providers and health care organizations will have to closely scrutinize their current processes of care. To do this, a value chain analysis can be performed to ensure that only the most efficient steps are followed in patient care. Ultimately this will produce a higher quality or equal quality product for less cost by eliminating wasteful steps along the way.
Barbara, D J; Morton, A; Spence, N J; Miller, A
1995-09-01
Immunocapture reverse transcriptase-polymerase chain reaction (RT-PCR) followed by restriction fragment length polymorphism (RFLP) analysis of the product has been shown to be an effective procedure for discriminating serologically indistinguishable isolates of two plant viruses, raspberry bushy dwarf (RBDV) and zucchini yellow mosaic (ZYMV). For both viruses, only limited sequence information was available at the time of primer design, but most of the isolates which were tested could be amplified (the one exception being a serologically quite distinct isolate of ZYMV). Restriction endonucleases revealing diagnostic RFLPs were readily identified. Each of two isolates of ZYMV could be detected in the presence of the other and the relative proportions approximately quantified by visual estimation of the relative intensity of the appropriate bands. A range of isolates of different RBDV pathotypes were compared; isolates were grouped in ways that accorded with their known history. Computer analysis of the published sequence from which the primers had been derived showed the sequenced isolate to be identical with an isolate imported from the USSR. The PCR/RFLP procedure is rapid (it can be completed in less than 2 days), effective and will probably be generally applicable to distinguishing closely related virus isolates, even where little sequence information is available.
Creative industries value chain: The value chain logic in supply chain relationships
Emilia Madudová
2017-01-01
The purpose of this paper is to provide a deeper look into value chain logic in supply chain relationships in a creative industries value chains. In recent years, value has been recognized as a key factor in better understanding of consumer behavior and gaining a competitive advantage. In a value chain, added value should be defined at every step of the chain. There should be defined activity which adds value as well as the activity that subtracts any value. The total value can be then calcul...
Approximating Markov Chains: What and why
International Nuclear Information System (INIS)
Pincus, S.
1996-01-01
Much of the current study of dynamical systems is focused on geometry (e.g., chaos and bifurcations) and ergodic theory. Yet dynamical systems were originally motivated by an attempt to open-quote open-quote solve,close-quote close-quote or at least understand, a discrete-time analogue of differential equations. As such, numerical, analytical solution techniques for dynamical systems would seem desirable. We discuss an approach that provides such techniques, the approximation of dynamical systems by suitable finite state Markov Chains. Steady state distributions for these Markov Chains, a straightforward calculation, will converge to the true dynamical system steady state distribution, with appropriate limit theorems indicated. Thus (i) approximation by a computable, linear map holds the promise of vastly faster steady state solutions for nonlinear, multidimensional differential equations; (ii) the solution procedure is unaffected by the presence or absence of a probability density function for the attractor, entirely skirting singularity, fractal/multifractal, and renormalization considerations. The theoretical machinery underpinning this development also implies that under very general conditions, steady state measures are weakly continuous with control parameter evolution. This means that even though a system may change periodicity, or become chaotic in its limiting behavior, such statistical parameters as the mean, standard deviation, and tail probabilities change continuously, not abruptly with system evolution. copyright 1996 American Institute of Physics
On the dynamics of chain systems. [applications in manipulator and human body models
Huston, R. L.; Passerello, C. E.
1974-01-01
A computer-oriented method for obtaining dynamical equations of motion for chain systems is presented. A chain system is defined as an arbitrarily assembled set of rigid bodies such that adjoining bodies have at least one common point and such that closed loops are not formed. The equations of motion are developed through the use of Lagrange's form of d'Alembert's principle. The method and procedure is illustrated with an elementary study of a tripod space manipulator. The method is designed for application with systems such as human body models, chains and cables, and dynamic finite-segment models.
Quantitative models for sustainable supply chain management
DEFF Research Database (Denmark)
Brandenburg, M.; Govindan, Kannan; Sarkis, J.
2014-01-01
and directions of this research area, this paper provides a content analysis of 134 carefully identified papers on quantitative, formal models that address sustainability aspects in the forward SC. It was found that a preponderance of the publications and models appeared in a limited set of six journals......Sustainability, the consideration of environmental factors and social aspects, in supply chain management (SCM) has become a highly relevant topic for researchers and practitioners. The application of operations research methods and related models, i.e. formal modeling, for closed-loop SCM...... and reverse logistics has been effectively reviewed in previously published research. This situation is in contrast to the understanding and review of mathematical models that focus on environmental or social factors in forward supply chains (SC), which has seen less investigation. To evaluate developments...
Chersi, Fabian; Ferro, Marcello; Pezzulo, Giovanni; Pirrelli, Vito
2011-01-01
Action and language are known to be organized as closely-related brain subsystems. An Italian CNR project implemented a computational neural model where the ability to form chains of goal-directed actions and chains of linguistic units relies on a unified memory architecture obeying the same organizing principles.
The molecular spin filter constructed from 1D organic chain
International Nuclear Information System (INIS)
Chen, Wei; Xu, Ning; Wang, Baolin; Bian, Baoan
2014-01-01
We proposed a molecular spin filter, which is constructed from the 1D metallic organic chain (Fe n+1 (C 6 H 4 ) n ). The spin-polarized transport properties of the molecular spin filter are explored by combining density functional theory with nonequilibrium Green's function formalism. Theoretical results reveal that Fe n+1 (C 6 H 4 ) n molecular chain exhibits robust spin filtering effect, and only the spin-down electrons can transmit through the molecular chain. At the given bias voltage window [−1 eV,1 eV], the calculated spin filter efficiency is close to 100% in the case of n≥3. We find that the effect of spin polarization origin from both Fe n+1 and (C 6 H 4 ) n . In addition, negative difference resistance behavior appears in Fe n+1 (C 6 H 4 ) n molecular chain. The results can help us understand the spin transport properties of organic molecular chain. - Highlights: • Theoretical results reveal that Fe n+1 (C 6 H 4 ) n molecular chain exhibits robust spin filtering effect. • The effect of spin polarization origin from both of Fe n+1 and (C 6 H 4 ) n . • Negative difference resistance behavior appears in Fe n+1 (C 6 H 4 ) n molecular chain
Agency Problem and Hedging in Agri-Food Chains: Model and Application
Kuwornu, J.K.M.; Kuiper, W.E.; Pennings, J.M.E.
2009-01-01
The last 4 decades have seen the transformation of food supply chains from being supply driven to becoming much more closely integrated with consumer demand. With this development, the transaction mechanism in food marketing channels has changed from an open-market mechanism to coordination through
Standard handbook of chains chains for power transmission and material handling
2005-01-01
A BRIEF HISTORY OF THE DEVELOPMENT OF CHAINEarly DevelopmentsCog ChainCast Detachable ChainCast Pintle ChainPrecision Roller ChainEngineering Steel ChainSilent ChainFlat-Top ChainTerminologyA CHAIN OVERVIEW: USES AND ADVANTAGESGeneralTypes of ChainScope of Chains CoveredStyles and Forms of ChainsStraight and Offset Link ChainsChains With and Without RollersUses of ChainStandard Chains and Their UsesThe Advantages of Chains in ApplicationsAdvantages of Roller Chains in DrivesAdvantages of Silent Chain Drives
Directory of Open Access Journals (Sweden)
Hao Sun
2015-04-01
Full Text Available Purpose: the aim of this paper is to investigate the closed-loop supply chain (CLSC network equilibrium wiht the consideration of three practical factors: two complementary types of suppliers, risk-averse character of the manufacturer and capacity constraints of the suppliers. Design/methodology/approach: The equilibrium of various decision makers including the suppliers, the manufacturers, the retailers, the collectors and the demand markets are modeled via finite-dimensional variational inequality, respectively. Then the governing CLSC network equilibrium model is established. The logarithmic-quadratic proximal prediction-correction algorithm is designed to solve the variational inequality model. Numerical examples are given to analyze the impact of return rate, risk-averse degree and capacity constraints on the network equilibrium under different product BOMs. Findings: with the increase of return rate, the profits of various channel members and the performance of the CLSC system will improve. There is a contradiction between profit maximization and risk minimization for the manufacturers. Moreover, the economic behavior of the CLSC is likely to be limited by the capacity constraints of the suppliers. Originality/value: Prior to this paper, few papers have addressed with the CLSC network equilibrium considering some practical factors. They assume all the suppliers are identical and all the decision-makers are risk neutral. Furthermore, the production capacities of all suppliers are assumed to be infinite or large enough. To fill the gap, this paper examines the influences of two-type suppliers, risk aversion and capacity constraints upon the CLSC network equilibrium.
Characterization of the fine specificity of peptide antibodies to HLA-DQ beta-chain molecules
DEFF Research Database (Denmark)
Petersen, J S; Atar, D; Karlsen, Alan E
1990-01-01
In an attempt to produce epitope specific antisera which could distinguish two closely associated HLA-DQ beta-chain alleles, we immunized 20 rabbits with synthetic peptides representing sequences from the first domain of the HLA-DQw8 and -DQw7 beta-chain molecules, differing only by one amino acid...... in position 57. Several of the antisera in immunoblotting specifically recognized either the HLA-DQw7 or the HLA-DQw8 beta-chain allele as previously reported. The fine specificity of the antisera was tested in ELISA using synthetic peptides of varying length as solid phase antigen. Two out of the 20 antisera...
Elements of automata theory and the theory of Markov chains. [Self-organizing control systems
Energy Technology Data Exchange (ETDEWEB)
Lind, M
1975-03-01
Selected topics from automata theory and the theory of Markov chains are treated. In particular, finite-memory automata are discussed in detail, and the results are used to formulate an automation model of a class of continuous systems. Stochastic automata are introduced as a natural generalization of the deterministic automaton. Markov chains are shown to be closely related to stochastic automata. Results from Markov chain theory are thereby directly applicable to analysis of stochastic automata. This report provides the theoretical foundation for the investigation in Riso Report No. 315 of a class of self-organizing control systems. (25 figures) (auth)
Development Value Chains meet Business Supply Chains : The concept of Global Value Chains unraveled
S. Drost (Sarah); J.C.A.C. van Wijk (Jeroen); S.R. Vellema (Sietze)
2011-01-01
textabstractValue chain promotion is considered a key element of private sector development strategies and pro-poor growth. However, (value) chain concepts are rather complex and unclear. This paper unravels the concept of global value chains and studies the diversity of key value chain-related
Dimer coverings on random multiple chains of planar honeycomb lattices
International Nuclear Information System (INIS)
Ren, Haizhen; Zhang, Fuji; Qian, Jianguo
2012-01-01
We study dimer coverings on random multiple chains. A multiple chain is a planar honeycomb lattice constructed by successively fusing copies of a ‘straight’ condensed hexagonal chain at the bottom of the previous one in two possible ways. A random multiple chain is then generated by admitting the Bernoulli distribution on the two types of fusing, which describes a zeroth-order Markov process. We determine the expectation of the number of the pure dimer coverings (perfect matchings) over the ensemble of random multiple chains by the transfer matrix approach. Our result shows that, with only two exceptions, the average of the logarithm of this expectation (i.e., the annealed entropy per dimer) is asymptotically nonzero when the fusing process goes to infinity and the length of the hexagonal chain is fixed, though it is zero when the fusing process and the length of the hexagonal chain go to infinity simultaneously. Some numerical results are provided to support our conclusion, from which we can see that the asymptotic behavior fits well to the theoretical results. We also apply the transfer matrix approach to the quenched entropy and reveal that the quenched entropy of random multiple chains has a close connection with the well-known Lyapunov exponent of random matrices. Using the theory of Lyapunov exponents we show that, for some random multiple chains, the quenched entropy per dimer is strictly smaller than the annealed one when the fusing process goes to infinity. Finally, we determine the expectation of the free energy per dimer over the ensemble of the random multiple chains in which the three types of dimers in different orientations are distinguished, and specify a series of non-random multiple chains whose free energy per dimer is asymptotically equal to this expectation. (paper)
Re-Distribution of Value Chain Activities Following Acquisition in the Brewery Sector
DEFF Research Database (Denmark)
Gammelgaard, Jens; Hobdari, Bersant
. Over time, some subsidiaries gained new value chain mandates or they substantially increased their scale in terms of production capacities or the markets in which they operated. From the practical point of view, this implies managers of the acquiring firm must pay close attention to the form and extent......In this paper, we investigate post-acquisition integration of acquired firms and subsequent developments in new subsidiary strategic responsibilities in value-chain activities. Using comparative case study methodology, we illustrate the forms, degrees and evolution of strategic responsibilities...
Alpha-chain states in 4N-nuclei from 20Ne to 32S
International Nuclear Information System (INIS)
Merchant, A.C.; Rae, W.D.M.
1992-01-01
A 6α-chain state has recently been discovered in 24 Mg which is some 16--17 MeV above the 6α-breakup threshold and yet paradoxically only 4--5 MeV wide. This surprising discovery raises the question of the possible existence of Nα-chain states in other 4N-nuclei. The excitation energy of this 6α-chain state is very close to the value predicted by the Bloch-Brink cluster model. Therefore, to aid the experimental search for similar states in other nuclei, we present here predictions of the excitation energies of the Nα-chain state bandheads in the 4N-nuclei from 20 Ne to 32 S obtained using the Bloch-Brink cranked cluster model with the Brink-Boeker effective interaction and free variation of all parameters
Jahangoshai Rezaee, Mustafa; Yousefi, Samuel; Hayati, Jamileh
2017-06-01
Supplier selection and allocation of optimal order quantity are two of the most important processes in closed-loop supply chain (CLSC) and reverse logistic (RL). So that providing high quality raw material is considered as a basic requirement for a manufacturer to produce popular products, as well as achieve more market shares. On the other hand, considering the existence of competitive environment, suppliers have to offer customers incentives like discounts and enhance the quality of their products in a competition with other manufacturers. Therefore, in this study, a model is presented for CLSC optimization, efficient supplier selection, as well as orders allocation considering quantity discount policy. It is modeled using multi-objective programming based on the integrated simultaneous data envelopment analysis-Nash bargaining game. In this study, maximizing profit and efficiency and minimizing defective and functions of delivery delay rate are taken into accounts. Beside supplier selection, the suggested model selects refurbishing sites, as well as determining the number of products and parts in each network's sector. The suggested model's solution is carried out using global criteria method. Furthermore, based on related studies, a numerical example is examined to validate it.
Coordinating a Supply Chain with Price and Advertisement Dependent Stochastic Demand
Li, Liying; Wang, Yong; Yan, Xiaoming
2013-01-01
This paper investigates pricing and ordering as well as advertising coordination issues in a single-manufacturer single-retailer supply chain, where the manufacturer sells a newsvendor-type product through the retailer who faces a stochastic demand depending on both retail price and advertising expenditure. Under the assumption that the market demand has a multiplicative functional form, the Stackelberg and cooperative game models are developed, and the closed form solution to each model is provided as well. Comparisons and insights are presented. We show that a properly designed revenue-cost-sharing contract can achieve supply chain coordination and lead to a Pareto improving win-win situation for channel members. We also discuss the allocation of the extra joint profit according to individual supply chain members' risk preferences and negotiating powers. PMID:24453832
Coordinating a Supply Chain with Price and Advertisement Dependent Stochastic Demand
Directory of Open Access Journals (Sweden)
Liying Li
2013-01-01
Full Text Available This paper investigates pricing and ordering as well as advertising coordination issues in a single-manufacturer single-retailer supply chain, where the manufacturer sells a newsvendor-type product through the retailer who faces a stochastic demand depending on both retail price and advertising expenditure. Under the assumption that the market demand has a multiplicative functional form, the Stackelberg and cooperative game models are developed, and the closed form solution to each model is provided as well. Comparisons and insights are presented. We show that a properly designed revenue-cost-sharing contract can achieve supply chain coordination and lead to a Pareto improving win-win situation for channel members. We also discuss the allocation of the extra joint profit according to individual supply chain members’ risk preferences and negotiating powers.
Coordinating a supply chain with price and advertisement dependent stochastic demand.
Li, Liying; Wang, Yong; Yan, Xiaoming
2013-01-01
This paper investigates pricing and ordering as well as advertising coordination issues in a single-manufacturer single-retailer supply chain, where the manufacturer sells a newsvendor-type product through the retailer who faces a stochastic demand depending on both retail price and advertising expenditure. Under the assumption that the market demand has a multiplicative functional form, the Stackelberg and cooperative game models are developed, and the closed form solution to each model is provided as well. Comparisons and insights are presented. We show that a properly designed revenue-cost-sharing contract can achieve supply chain coordination and lead to a Pareto improving win-win situation for channel members. We also discuss the allocation of the extra joint profit according to individual supply chain members' risk preferences and negotiating powers.
SUPPLY CHAIN STRATEGIES IN THE CONTEXT OF AN E-COMMERCE CHAIN (E-CHAIN
Directory of Open Access Journals (Sweden)
João Gilberto Mendes do Reis
2014-05-01
Full Text Available This paper purpose to explore the relationships between supply chain strategies and product performance in retail e-commerce. In this case, we concern that in current, in order to bear up under competition, organizations have to manage their supply chains so that they meet the needs of their final customers. With this concept in mind, the research presented in this study focuses on establishing the right strategy for supply chains according to their product segment. Thus, after a Literature Review, the paper explain a methodology based in different authors studies. Finally the article focuses on a pratical case in e-commerce retail that describes its application in this field. The research shows that it is possible to use a methodology for classifying supply chains using chain strategies and product features. The use of the right strategy for supply chains will improve the competitive advantage of businesses. One limitation is that the methodology study focuses on only two e-commerce segment; future studies may go further in refining the proposed framework for other segments. The aim of this research is to offer businesses a model for evaluating supply chains, allowing them to improve the performance of their products and services by using the right strategy for supply chains. The classification proposal of this paper presents an original model for classification of supply chains based on different studies on the theme.
Forecasting return products in an integrated forward/reverse supply chain utilizing an ANFIS
Directory of Open Access Journals (Sweden)
Kumar D. Thresh
2014-09-01
Full Text Available Interests in Closed-Loop Supply Chain (CLSC issues are growing day by day within the academia, companies, and customers. Many papers discuss profitability or cost reduction impacts of remanufacturing, but a very important point is almost missing. Indeed, there is no guarantee about the amounts of return products even if we know a lot about demands of first products. This uncertainty is due to reasons such as companies’ capabilities in collecting End-of-Life (EOL products, customers’ interests in returning (and current incentives, and other independent collectors. The aim of this paper is to deal with the important gap of the uncertainties of return products. Therefore, we discuss the forecasting method of return products which have their own open-loop supply chain. We develop an integrated two-phase methodology to cope with the closed-loop supply chain design and planning problem. In the first phase, an Adaptive Network Based Fuzzy Inference System (ANFIS is presented to handle the uncertainties of the amounts of return product and to determine the forecasted return rates. In the second phase, and based on the results of the first one, the proposed multi-echelon, multi-product, multi-period, closed-loop supply chain network is optimized. The second-phase optimization is undertaken based on using general exact solvers in order to achieve the global optimum. Finally, the performance of the proposed forecasting method is evaluated in 25 periods using a numerical example, which contains a pattern in the returning of products. The results reveal acceptable performance of the proposed two-phase optimization method. Based on them, such forecasting approaches can be applied to real-case CLSC problems in order to achieve more reliable design and planning of the network
The Albedos of Kepler's Close-in super-Earths
Demory, Brice-Olivier
2014-01-01
Exoplanet research focusing on the characterization of super-Earths is currently limited to those handful targets orbiting bright stars that are amenable to detailed study. This Letter proposes to look at alternative avenues to probe the surface and atmospheric properties of this category of planets, known to be ubiquitous in our galaxy. I conduct Markov Chain Monte Carlo lightcurve analyses for 97 Kepler close-in $R_P \\lesssim 2.0 R_{\\oplus}$ super-Earth candidates with the aim to detect the...
Path-integral approach to the dynamics of a random chain with rigid constraints
International Nuclear Information System (INIS)
Ferrari, Franco; Paturej, Jaroslaw; Vilgis, Thomas A.
2008-01-01
In this work the dynamics of a chain consisting of a set of beads attached to the ends of segments of fixed lengths is investigated. The chain fluctuates at constant temperature in a viscous medium. For simplicity, all interactions among the beads have been switched off and the number of spatial dimensions has been limited to two. In the limit in which the chain becomes a continuous system, its behavior may be described by a path integral, in which the rigid constraints coming from the infinitesimally small segments are imposed by means of a functional δ function. In this way a model of the dynamics of the chain is obtained, which closely resembles a two-dimensional nonlinear σ model. The partition function of this generalized nonlinear σ model is computed explicitly for a ring-shaped chain in the semiclassical approximation. The behavior of the chain at both long and short scales of time and distances is investigated. The connection between the generalized nonlinear σ model presented here and the Rouse model is discussed
Romero-Franco, Natalia; Montaño-Munuera, Juan Antonio; Jiménez-Reyes, Pedro
2017-01-01
Knee joint position sense (JPS) is a key parameter for optimum performance in many sports but is frequently negatively affected by injuries and/or fatigue during training sessions. Although evaluation of JPS may provide key information to reduce the risk of injury, it often requires expensive and/or complex tools that make monitoring proprioceptive deterioration difficult. To analyze the validity and reliability of a digital inclinometer to measure knee JPS in a closed kinetic chain (CKC). The validity and intertester and intratester reliability of a digital inclinometer for measuring knee JPS were assessed. Biomechanics laboratory. 10 athletes (5 men and 5 women; 26.2 ± 1.3 y, 71.7 ± 12.4 kg; 1.75 ± 0.09 m; 23.5 ± 3.9 kg/m 2 ). Knee JPS was measured in a CKC. Absolute angular error (AAE) of knee JPS in a CKC. Intraclass correlation coefficient (ICC) and standard error of the mean (SEM) were calculated to determine the validity and reliability of the inclinometer. Data showed that the inclinometer had a high level of validity compared with an isokinetic dynamometer (ICC = 1.0, SEM = 1.39, p AutoCAD video analysis, inclinometer validity was very high (ICC = 0.980, SEM = 3.46, p < 0.001) for measuring AAE during knee JPS in a CKC. In addition, the intertester reliability of the inclinometer for obtaining AAE was very high (ICC = .994, SEM = 1.67, p < 0.001). The inclinometer provides a valid and reliable method for assessing knee JPS in a CKC. Health and sports professionals could take advantage of this tool to monitor proprioceptive deterioration in athletes.
Integrated forward and reverse supply chain: A tire case study.
Pedram, Ali; Yusoff, Nukman Bin; Udoncy, Olugu Ezutah; Mahat, Abu Bakar; Pedram, Payam; Babalola, Ayo
2017-02-01
This paper attempts to integrate both a forward and reverse supply chain to design a closed-loop supply chain network (CLSC). The problem in the design of a CLSC network is uncertainty in demand, return products and the quality of return products. Scenario analyses are generated to overcome this uncertainty. In contrast to the existing supply chain network design models, a new application of a CLSC network was studied in this paper to reduce waste. A multi-product, multi-tier mixed integer linear model is developed for a CLSC network design. The main objective is to maximize profit and provide waste management decision support in order to minimize pollution. The result shows applicability of the model in the tire industry. The model determines the number and the locations of facilities and the material flows between these facilities. Copyright © 2016 Elsevier Ltd. All rights reserved.
Prospects of closed-circuit television in detecting surface defects
International Nuclear Information System (INIS)
Kaisler, L. et al.
The use is discussed of closed-circuit television for optical in-service testing of surface defects of nuclear reactors. Experience gained by UJV Rez with in-service testing of the WWR-S reactor is briefly reported. Main attention is devoted to recognizability of defects and to determining the fundamental conditions of the applicability and limitations of the closed-circuit television method. In experiments, resolution of the method was tested and the role of the human factor was assessed in evaluating the results. The need was stressed of thorough training of operators. Based on the experiments conducted, considerations are presented regarding modifications of the individual elements of the tv chain aimed at improved quality of information and a limited role of the observer. (B.S.)
Engineering electronic states of periodic and quasiperiodic chains by buckling
Mukherjee, Amrita; Nandy, Atanu; Chakrabarti, Arunava
2017-07-01
The spectrum of spinless, non-interacting electrons on a linear chain that is buckled in a non-uniform, quasiperiodic manner is investigated within a tight binding formalism. We have addressed two specific cases, viz., a perfectly periodic chain wrinkled in a quasiperiodic Fibonacci pattern, and a quasiperiodic Fibonacci chain, where the buckling also takes place in a Fibonacci pattern. The buckling brings distant neighbors in the parent chain to close proximity, which is simulated by a tunnel hopping amplitude. It is seen that, in the perfectly ordered case, increasing the strength of the tunnel hopping (that is, bending the segments more) absolutely continuous density of states is retained towards the edges of the band, while the central portion becomes fragmented and host subbands of narrowing widths containing extended, current carrying states, and multiple isolated bound states formed as a result of the bending. A switching ;on; and ;off; of the electronic transmission can thus be engineered by buckling. On the other hand, in the second example of a quasiperiodic Fibonacci chain, imparting a quasiperiodic buckling is found to generate continuous subband(s) destroying the usual multifractality of the energy spectrum. We present exact results based on a real space renormalization group analysis, that is corroborated by explicit calculation of the two terminal electronic transport.
Chained Iron Microparticles for Directionally Controlled Actuation of Soft Robots.
Schmauch, Marissa M; Mishra, Sumeet R; Evans, Benjamin A; Velev, Orlin D; Tracy, Joseph B
2017-04-05
Magnetic field-directed self-assembly of magnetic particles in chains is useful for developing directionally responsive materials for applications in soft robotics. Using materials with greater complexity allows advanced functions, while still using simple device architectures. Elastomer films containing chained magnetic microparticles were prepared through solvent casting and formed into magnetically actuated lifters, accordions, valves, and pumps. Chaining both enhances actuation and imparts a directional response. Cantilevers used as lifters were able to lift up to 50 times the mass of the polymer film. We introduce the "specific torque", the torque per field per mass of magnetic particles, as a figure of merit for assessing and comparing the performance of lifters and related devices. Devices in this work generated specific torques of 68 Nm/kgT, which is significantly higher than in previously reported actuators. Applying magnetic fields to folded accordion structures caused extension and compression, depending on the accordion's orientation. In peristaltic pumps comprised of composite tubes containing embedded chains, magnetic fields caused a section of the tube to pinch closed where the field was applied. These results will facilitate both the further development of soft robots based on chained magnetic particles and efforts to engineer materials with higher specific torque.
Interrelated Dimensional Chains in Predicting Accuracy of Turbine Wheel Assembly Parameters
Yanyukina, M. V.; Bolotov, M. A.; Ruzanov, N. V.
2018-03-01
The working capacity of any device primarily depends on the assembly accuracy which, in its turn, is determined by the quality of each part manufactured, i.e., the degree of conformity between final geometrical parameters and the set ones. However, the assembly accuracy depends not only on a qualitative manufacturing process but also on the assembly process correctness. In this connection, there were preliminary calculations of assembly stages in terms of conformity to real geometrical parameters with their permissible values. This task is performed by means of the calculation of dimensional chains. The calculation of interrelated dimensional chains in the aircraft industry requires particular attention. The article considers the issues of dimensional chain calculation modelling by the example of the turbine wheel assembly process. The authors described the solution algorithm in terms of mathematical statistics implemented in Matlab. The paper demonstrated the results of a dimensional chain calculation for a turbine wheel in relation to the draw of turbine blades to the shroud ring diameter. Besides, the article provides the information on the influence of a geometrical parameter tolerance for the dimensional chain link elements on a closing one.
Power of Companies in Supply Chains and Their Effect on Network Development
Directory of Open Access Journals (Sweden)
Tamás Brányi
2015-01-01
Full Text Available A general supply chain functions as a closed cluster and consists of at least three companies: supplier, producer and buyer. In an optimal case the companies within a supply chain are well integrated, partnership rests on trust which results in common strategic decisions. Business practices show that there is a stronger company within the chain that uses its power position to influence network development. The objective of the research is to measure how and what kind of power position is needed to influence the supply chain. The hypothesis states, that power and network development are opposite effects in a supply chain. Statistical examination of data gained from 221 companies state that the company with power position has advantages if the supply chain extends. SPSS analysis proves that the hypothesis is false and opens a new direction of research. Companies within the supply chain have to cope with power structures while cooperating with each other. They tend to look for solutions to ease dependency. Using or misusing power has several factors; mainly they are inherited from the strongest link of the supply chain. This is usually a problem but the results of the statistical analysis show that still a win-win situation is needed for the companies in order to deepen the cooperation. To conclude this research the data shows that the goal is to be more competitive as a chain, not just as a company.
International Nuclear Information System (INIS)
1994-07-01
In order to discover a more accurate and selective measuring method for the identification of individual flow-noise pollution sources on wind turbines blades, measuring equipment based on a chain of microphones was developed. The principle underlying the design of this equipment is that signals from a number of microphones can be interpreted. Thus the microphones can register noise from sections of the rotary blade and unwished-for noise is eliminated. The gating technique ensures that noises from individual blades can be separated and that clarity is improved. In addition to this, noise can be determined close to the source. The chain consists of 8 microphones placed in a row at adjustable distances. Measurements are registered on tapes as are the trigger signals for the blade passage. The computer processes the measurement results and unnecessary noise is depressed. The listening angles can also be changed electronically so that the doppler effect can be corrected. Results confirmed that the equipment operated satisfactorily and could also be used in relation to noise pollution in power plants as it is especially effective in depressing excess, and cutting out outside, noise and registers accurately individual sources of noise helped by its ability to ''listen '' at varying angles to the source. (AB)
Decision-Making for Supply Chain Integration Supply Chain Integration
Lettice, Fiona; Durowoju, Olatunde
2012-01-01
Effective supply chain integration, and the tight co-ordination it creates, is an essential pre-requisite for successful supply chain management. Decision-Making for Supply Chain Integration is a practical reference on recent research in the area of supply chain integration focusing on distributed decision-making problems. Recent applications of various decision-making tools for integrating supply chains are covered including chapters focusing on: •Supplier selection, pricing strategy and inventory decisions in multi-level supply chains, •RFID-enabled distributed decision-making, •Operational risk issues and time-critical decision-making for sensitive logistics nodes, Modelling end to end processes to improve supply chain integration, and •Integrated systems to improve service delivery and optimize resource use. Decision-Making for Supply Chain Integration provides an insight into the tools and methodologies of this field with support from real-life case studies demonstrating successful application ...
Trigonometric version of quantum–classical duality in integrable systems
Directory of Open Access Journals (Sweden)
M. Beketov
2016-02-01
Full Text Available We extend the quantum–classical duality to the trigonometric (hyperbolic case. The duality establishes an explicit relationship between the classical N-body trigonometric Ruijsenaars–Schneider model and the inhomogeneous twisted XXZ spin chain on N sites. Similarly to the rational version, the spin chain data fixes a certain Lagrangian submanifold in the phase space of the classical integrable system. The inhomogeneity parameters are equal to the coordinates of particles while the velocities of classical particles are proportional to the eigenvalues of the spin chain Hamiltonians (residues of the properly normalized transfer matrix. In the rational version of the duality, the action variables of the Ruijsenaars–Schneider model are equal to the twist parameters with some multiplicities defined by quantum (occupation numbers. In contrast to the rational version, in the trigonometric case there is a splitting of the spectrum of action variables (eigenvalues of the classical Lax matrix. The limit corresponding to the classical Calogero–Sutherland system and quantum trigonometric Gaudin model is also described as well as the XX limit to free fermions.
Scaling of the polarization amplitude in quantum many-body systems in one dimension
Kobayashi, Ryohei; Nakagawa, Yuya O.; Fukusumi, Yoshiki; Oshikawa, Masaki
2018-04-01
Resta proposed a definition of the electric polarization in one-dimensional systems in terms of the ground-state expectation value of the large gauge transformation operator. Vanishing of the expectation value in the thermodynamic limit implies that the system is a conductor. We study Resta's polarization amplitude (expectation value) in the S =1 /2 XXZ chain and its several generalizations, in the gapless conducting Tomonaga-Luttinger liquid phase. We obtain an analytical expression in the lowest-order perturbation theory about the free fermion point (XY chain) and an exact result for the Haldane-Shastry model with long-range interactions. We also obtain numerical results, mostly using the exact diagonalization method. We find that the amplitude exhibits a power-law scaling in the system size (chain length) and vanishes in the thermodynamic limit. On the other hand, the exponent depends on the model even when the low-energy limit is described by the Tomonaga-Luttinger liquid with the same Luttinger parameter. We find that a change in the exponent occurs when the Umklapp term(s) are eliminated, suggesting the importance of the Umklapp terms.
Trigonometric version of quantum–classical duality in integrable systems
Energy Technology Data Exchange (ETDEWEB)
Beketov, M., E-mail: beketov@phystech.edu [MIPT, Inststitutskii per. 9, 141700, Dolgoprudny, Moscow region (Russian Federation); Liashyk, A., E-mail: a.liashyk@gmail.com [National Research University Higher School of Economics, Myasnitskaya str. 20, 101000, Moscow (Russian Federation); BITP, Metrolohichna str. 14-b, 03680, Kiev (Ukraine); Zabrodin, A., E-mail: zabrodin@itep.ru [National Research University Higher School of Economics, Myasnitskaya str. 20, 101000, Moscow (Russian Federation); Institute of Biochemical Physics, Kosygina str. 4, 119991, Moscow (Russian Federation); ITEP, Bolshaya Cheremushkinskaya str. 25, 117218, Moscow (Russian Federation); Zotov, A., E-mail: zotov@mi.ras.ru [Steklov Mathematical Institute, RAS, Gubkina str. 8, 119991, Moscow (Russian Federation); ITEP, Bolshaya Cheremushkinskaya str. 25, 117218, Moscow (Russian Federation); MIPT, Inststitutskii per. 9, 141700, Dolgoprudny, Moscow region (Russian Federation)
2016-02-15
We extend the quantum–classical duality to the trigonometric (hyperbolic) case. The duality establishes an explicit relationship between the classical N-body trigonometric Ruijsenaars–Schneider model and the inhomogeneous twisted XXZ spin chain on N sites. Similarly to the rational version, the spin chain data fixes a certain Lagrangian submanifold in the phase space of the classical integrable system. The inhomogeneity parameters are equal to the coordinates of particles while the velocities of classical particles are proportional to the eigenvalues of the spin chain Hamiltonians (residues of the properly normalized transfer matrix). In the rational version of the duality, the action variables of the Ruijsenaars–Schneider model are equal to the twist parameters with some multiplicities defined by quantum (occupation) numbers. In contrast to the rational version, in the trigonometric case there is a splitting of the spectrum of action variables (eigenvalues of the classical Lax matrix). The limit corresponding to the classical Calogero–Sutherland system and quantum trigonometric Gaudin model is also described as well as the XX limit to free fermions.
Resilience of hidden order to symmetry-preserving disorder
Strinati, Marcello Calvanese; Rossini, Davide; Fazio, Rosario; Russomanno, Angelo
2017-12-01
We study the robustness of nonlocal string order in two paradigmatic disordered spin-chain models, a spin-1/2 cluster-Ising and a spin-1 XXZ Heisenberg chain. In the clean case, they both display a transition from antiferromagnetic to string order. Applying a disorder, which preserves the Hamiltonian symmetries, we find that the transition persists in both models. In the disordered cluster-Ising model, we can study the transition analytically—by applying the strongest coupling renormalization group —and numerically—by exploiting integrability to study the antiferromagnetic and string order parameters. We map the model into a quadratic fermion chain, where the transition appears as a change in the number of zero-energy edge modes. We also explore its zero-temperature-singularity behavior and find a transition from a nonsingular to a singular region, at a point that is different from the one separating nonlocal and local ordering. The disordered Heisenberg chain can be treated only numerically: by means of MPS-based simulations, we are able to locate the existence of a transition between antiferromagnetic and string-ordered phase, through the study of order parameters. Finally, we discuss possible connections of our findings with many-body localization.
Interactions of Bargaining Power and Introduction of Online Channel in Two Competing Supply Chains
Directory of Open Access Journals (Sweden)
Jie Wei
2018-01-01
Full Text Available This paper studies the effect of dual-channel format on supply chain’s competition ability and the effect of different bargaining powers on the competition between two supply chains and the optimal pricing decisions of all supply chain members when one supply chain introduces an online retailing channel. We develop four game models and obtain the optimal pricing decisions in closed form of these models and give some sensitivity analysis through numerical approach. Some new managerial insights are obtained as follows: Regardless of the two supply chain members’ bargaining forms, the optimal price, the maximal demand, and the maximal profit decrease as the self-price sensitivity decreases. The industry holds advantage in getting higher profit when the supply chain without online retailing channel is led by the retailer. In addition, we find that a manufacturer as a leader of its supply chain can get more profit when the competing supply chain’s leader is the manufacturer than when the competing supply chain’s leader is the retailer.
Quantum integrability and supersymmetric vacua
International Nuclear Information System (INIS)
Nekrasov, Nikita; Shatashvili, Samson
2009-01-01
Supersymmetric vacua of two dimensional N=4 gauge theories with matter, softly broken by the twisted masses down to N=2, are shown to be in one-to-one correspondence with the eigenstates of integrable spin chain Hamiltonians. Examples include: the Heisenberg SU(2) XXX spin chain which is mapped to the two dimensional U(N) theory with fundamental hypermultiplets, the XXZ spin chain which is mapped to the analogous three dimensional super-Yang-Mills theory compactified on a circle, the XYZ spin chain and eight-vertex model which are related to the four dimensional theory compactified on T 2 . A consequence of our correspondence is the isomorphism of the quantum cohomology ring of various quiver varieties, such as T * Gr(N,L) and the ring of quantum integrals of motion of various spin chains. The correspondence extends to any spin group, representations, boundary conditions, and inhomogeneity, it includes Sinh-Gordon and non-linear Schroedinger models as well as the dynamical spin chains like Hubbard model. These more general spin chains correspond to quiver gauge theories with twisted masses, with classical gauge groups. We give the gauge-theoretic interpretation of Drinfeld polynomials and Baxter operators. In the classical weak coupling limit our results make contact with Nakajima constructions. Toric compactifications of four dimensional N=2 theories lead to the instanton corrected Bethe equations. (author)
Port supply chain integration : analyzing biofuel supply chains
Stevens, Leonie C. E.; Vis, Iris F. A.
2016-01-01
This paper focuses on port supply chain integration to strengthen operational and business performance. We provide a structured and comprehensive method to enable port supply chain integration and demonstrate its applicability to the biofuel supply chain. We define the value proposition, role,
Ecosilient Index to assess the greenness and resilience of the upstream automotive supply chain
DEFF Research Database (Denmark)
Azevedo, S.G.; Govindan, Kannan; Carvalho, H.
2013-01-01
This paper suggests an Ecosilient Index to assess the greenness and resilience of automotive companies and the corresponding supply chain. An integrated assessment model is proposed based on green and resilient practices. The Delphi technique is used to obtain the weights of the supply chain para...... sector; this constitutes an initial effort to close the gap between theory and practice. Future research is needed to investigate the index applicability in different industry contexts........ to the greenness of this industry is to reduce energy consumption. The significant contributions to resilience are sourcing strategies that allow switching of suppliers, flexible supply base/flexible sourcing and creating total supply chain visibility. The proposed index was developed in the context of automotive...
Limit temperature for entanglement in generalized statistics
International Nuclear Information System (INIS)
Rossignoli, R.; Canosa, N.
2004-01-01
We discuss the main properties of general thermal states derived from non-additive entropic forms and their use for studying quantum entanglement. It is shown that all these states become more mixed as the temperature increases, approaching the full random state for T→∞. The formalism is then applied to examine the limit temperature for entanglement in a two-qubit XXZ Heisenberg chain, which exhibits the peculiar feature of being independent of the applied magnetic field in the conventional von Neumann based statistics. In contrast, this temperature is shown to be field dependent in a generalized statistics, even for small deviations from the standard form. Results for the Tsallis-based statistics are examined in detail
NLIE of Dirichlet sine-Gordon model for boundary bound states
International Nuclear Information System (INIS)
Ahn, Changrim; Bajnok, Zoltan; Palla, Laszlo; Ravanini, Francesco
2008-01-01
We investigate boundary bound states of sine-Gordon model on the finite-size strip with Dirichlet boundary conditions. For the purpose we derive the nonlinear integral equation (NLIE) for the boundary excited states from the Bethe ansatz equation of the inhomogeneous XXZ spin 1/2 chain with boundary imaginary roots discovered by Saleur and Skorik. Taking a large volume (IR) limit we calculate boundary energies, boundary reflection factors and boundary Luescher corrections and compare with the excited boundary states of the Dirichlet sine-Gordon model first considered by Dorey and Mattsson. We also consider the short distance limit and relate the IR scattering data with that of the UV conformal field theory
The q-deformed analogue of the Onsager algebra: Beyond the Bethe ansatz approach
International Nuclear Information System (INIS)
Baseilhac, Pascal
2006-01-01
The spectral properties of operators formed from generators of the q-Onsager non-Abelian infinite-dimensional algebra are investigated. Using a suitable functional representation, all eigenfunctions are shown to obey a second-order q-difference equation (or its degenerate discrete version). In the algebraic sector associated with polynomial eigenfunctions (or their discrete analogues), Bethe equations naturally appear. Beyond this sector, where the Bethe ansatz approach is not applicable in related massive quantum integrable models, the eigenfunctions are also described. The spin-half XXZ open spin chain with general integrable boundary conditions is reconsidered in light of this approach: all the eigenstates are constructed. In the algebraic sector which corresponds to special relations among the parameters, known results are recovered
Properties of linear integral equations related to the six-vertex model with disorder parameter II
International Nuclear Information System (INIS)
Boos, Hermann; Göhmann, Frank
2012-01-01
We study certain functions arising in the context of the calculation of correlation functions of the XXZ spin chain and of integrable field theories related to various scaling limits of the underlying six-vertex model. We show that several of these functions that are related to linear integral equations can be obtained by acting with (deformed) difference operators on a master function Φ. The latter is defined in terms of a functional equation and of its asymptotic behavior. Concentrating on the so-called temperature case, we show that these conditions uniquely determine the high-temperature series expansions of the master function. This provides an efficient calculation scheme for the high-temperature expansions of the derived functions as well. (paper)
... of heavy chain produced: Alpha Gamma Mu Alpha Heavy Chain Disease Alpha heavy chain disease (IgA heavy ... the disease or lead to a remission. Gamma Heavy Chain Disease Gamma heavy chain disease (IgG heavy ...
Halushka, Marc K; Eng, George; Collins, A Bernard; Judge, Daniel P; Semigran, Marc J; Stone, James R
2015-06-01
Accurate and rapid classification of cardiac amyloidosis is important for patient management. We have optimized the use of serum free light chain kappa and lambda values to differentiate immunoglobulin light chain amyloid (AL) amyloidosis from transthyretin amyloid and amyloid A using 85 cases of tissue-proven cardiac amyloidosis, in which there was direct classification of amyloidosis by mass spectrometry or immunofluorescence. The serum free light chain kappa/lambda ratios were non-overlapping for the three major groups: AL-lambda (0.01-0.41, n = 30), non-AL (0.52-2.7, n = 43), and AL-kappa (6.7-967, n = 12). A kappa/lambda ratio value between 0.5 and 5.0 had 100 % sensitivity and 100 % specificity for distinguishing AL amyloidosis from non-AL amyloidosis. This optimized range for serum light chain kappa/lambda ratio provides extremely robust classification of cardiac amyloidosis. Cases of cardiac amyloidosis in which the serum kappa/lambda free light chain ratio falls close to these new cutoff values may benefit most from direct amyloid subtyping.
Supply Chain Connectivity: Enhancing Participation in the Global Supply Chain
Patalinghug, Epictetus E.
2015-01-01
Supply chain connectivity is vital for the efficient flow of trade among APEC economies. This paper reviews the literature and supply chain management, describes the barriers to enhancing participation in global supply chain, analyzes the various measures of supply chain performance, and suggests steps for the Philippines to fully reap the benefits of the global value chain.
Forecasting return products in an integrated forward/reverse supply chain utilizing an ANFIS
DEFF Research Database (Denmark)
Kumar, D. T.; Soleimani, H.; Kannan, G.
2014-01-01
Interests in Closed-Loop Supply Chain (CLSC) issues are growing day by day within the academia, companies, and customers. Many papers discuss profitability or cost reduction impacts of remanufacturing, but a very important point is almost missing. Indeed, there is no guarantee about the amounts o...
Markov Chain Models for Stochastic Behavior in Resonance Overlap Regions
McCarthy, Morgan; Quillen, Alice
2018-01-01
We aim to predict lifetimes of particles in chaotic zoneswhere resonances overlap. A continuous-time Markov chain model isconstructed using mean motion resonance libration timescales toestimate transition times between resonances. The model is applied todiffusion in the co-rotation region of a planet. For particles begunat low eccentricity, the model is effective for early diffusion, butnot at later time when particles experience close encounters to the planet.
Pre-relaxation in weakly interacting models
Bertini, Bruno; Fagotti, Maurizio
2015-07-01
We consider time evolution in models close to integrable points with hidden symmetries that generate infinitely many local conservation laws that do not commute with one another. The system is expected to (locally) relax to a thermal ensemble if integrability is broken, or to a so-called generalised Gibbs ensemble if unbroken. In some circumstances expectation values exhibit quasi-stationary behaviour long before their typical relaxation time. For integrability-breaking perturbations, these are also called pre-thermalisation plateaux, and emerge e.g. in the strong coupling limit of the Bose-Hubbard model. As a result of the hidden symmetries, quasi-stationarity appears also in integrable models, for example in the Ising limit of the XXZ model. We investigate a weak coupling limit, identify a time window in which the effects of the perturbations become significant and solve the time evolution through a mean-field mapping. As an explicit example we study the XYZ spin-\\frac{1}{2} chain with additional perturbations that break integrability. One of the most intriguing results of the analysis is the appearance of persistent oscillatory behaviour. To unravel its origin, we study in detail a toy model: the transverse-field Ising chain with an additional nonlocal interaction proportional to the square of the transverse spin per unit length (2013 Phys. Rev. Lett. 111 197203). Despite being nonlocal, this belongs to a class of models that emerge as intermediate steps of the mean-field mapping and shares many dynamical properties with the weakly interacting models under consideration.
Numerical analysis of the performance of an atomic iodine laser amplifier chain
International Nuclear Information System (INIS)
Uchiyama, T.; Witte, K.J.
1981-05-01
The performance of an atomic iodine laser amplifier chain with output pulse powers close to 2 TW is analyzed by a numerical solution of the Maxwell-Bloch equations. Two subjects are discussed in detail. The first one refers to the pulse compression occurring in the chain as a result of saturation and some related aspects such as damage to components, self-focussing, correlation between the input and output pulse shapes, and the means of pulse shape control. The second deals with various schemes suited for achieving extraction efficiencies of about or larger than 55%. These include the single-pass and double-pass schemes, pulses with two carrier frequencies and a variation of the pulse carrier frequency. In addition, the response of the chain to a variation of those parameters which are most easily subject to change in a routine operation is investigated. (orig.)
Black-pigmented anaerobic rods in closed periapical lesions.
Bogen, G; Slots, J
1999-05-01
This study determined the frequency of Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella intermedia and Prevotella nigrescens in 20 closed periapical lesions associated with symptomatic and asymptomatic refractory endodontic disease. To deliniate possible oral sources of P. endodontalis, the presence of the organism was assessed in selected subgingival sites and saliva in the same study patients. Periapical samples were obtained by paper points during surgical endodontic procedures using methods designed to minimize contamination by non-endodontic microorganisms. Subgingival plaque samples were obtained by paper points from three periodontal pockets and from the pocket of the tooth associated with the closed periapical lesion. Unstimulated saliva was collected from the surface of the soft palate. Bacterial identification was performed using a species-specific polymerase chain reaction (PCR) detection method. P. endodontalis was not identified in any periapical lesion, even though subgingival samples from eight patients (40%) revealed the P. endodontalis-specific amplicon. P. gingivalis occurred in one periapical lesion that was associated with moderate pain. P. nigrescens, P. endodontalis and P. intermedia were not detected in any periapical lesion studied. Black-pigmented anaerobic rods appear to be infrequent inhabitants of the closed periapical lesion.
The square Ising model with second-neighbor interactions and the Ising chain in a transverse field
International Nuclear Information System (INIS)
Grynberg, M.D.; Tanatar, B.
1991-06-01
We consider the thermal and critical behaviour of the square Ising lattice with frustrated first - and second-neighbor interactions. A low-temperature domain wall analysis including kinks and dislocations shows that there is a close relation between this classical model and the Hamiltonian of an Ising chain in a transverse field provided that the ratio of the next-nearest to nearest-neighbor coupling, is close to 1/2. Due to the field inversion symmetry of the Ising chain Hamiltonian, the thermal properties of the classical system are symmetrical with respect to this coupling ratio. In the neighborhood of this regime critical exponents of the model turn out to belong to the Ising universality class. Our results are compared with previous Monte Carlo simulations. (author). 23 refs, 6 figs
Self-heating in Josephson junction chains. New insight from old circuits
Energy Technology Data Exchange (ETDEWEB)
Cole, Jared [Chemical and Quantum Physics, School of Applied Sciences, RMIT University, Melbourne, Victoria 3001 (Australia); Marthaler, Michael [Institute fuer Theoretische Festkoerperphysik, Karlsruhe Institute of Technology, 76128 Karlsruhe (Germany); Duty, Timothy [Centre for Engineered Quantum Systems (EQuS), School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia)
2016-07-01
The conduction properties of arrays of Josephson junctions are been studied for decades, yet the experimental results never really match the predictions of the idealised theoretical models. Many reasons have been given for this, including imperfections in the measurement, in the fabrication process or in the theoretical models used. Recently, using a combination of systematic numerical and experimental studies, the gap between theory and experiment is closing. As an example of this, we discuss the role of self-heating in the transport properties of one-dimensional Josephson junction chains. We show tantalising experimental measurements and how these can be compared to various theoretical models for the self-heating processes within the chains.
An introduction to integrable techniques in one-dimensional quantum systems
Franchini, Fabio
2017-01-01
This book introduces the reader to basic notions of integrable techniques for one-dimensional quantum systems. In a pedagogical way, a few examples of exactly solvable models are worked out to go from the coordinate approach to the Algebraic Bethe Ansatz, with some discussion on the finite temperature thermodynamics. The aim is to provide the instruments to approach more advanced books or to allow for a critical reading of research articles and the extraction of useful information from them. We describe the solution of the anisotropic XY spin chain; of the Lieb-Liniger model of bosons with contact interaction at zero and finite temperature; and of the XXZ spin chain, first in the coordinate and then in the algebraic approach. To establish the connection between the latter and the solution of two dimensional classical models, we also introduce and solve the 6-vertex model. Finally, the low energy physics of these integrable models is mapped into the corresponding conformal field theory. Through its style and t...
Directory of Open Access Journals (Sweden)
Trishna Saikia Baruah
2016-04-01
Full Text Available Background: Cerebral Palsy (CP describes a non- progressive but not unchanging disorder of movement and posture due to an insult to or anomaly of the developing brain. People with spastic diplegia typically walk slowly and have difficulties in performing activities such as walking running or jumping. Children with spastic diplegic cerebral palsy are relied more on cadence to increase speed. Hence, the purpose of this study is to compare the effectiveness of open and closed kinetic chain (OKC and CKC exercises in improving gait in spastic diplegic cerebral palsy. Methods: 30 children with spastic diplegic cerebral palsy of both genders with age 4-12 years was taken. Cadence and distance covered in 1Minute Walk Test was calculated before and after the test. The intervention for group A was CKC exercises and group B was OKC exercises for 3 days a week for 6 weeks and each session lasted for 30-45 minutes was given for both the groups. Results: Paired t-test was performed to find effectiveness of CKC and OKC improving gait in spastic diplegic CP to see the difference of means of 1minute walk, t = 10.789 which is significant (p = 0.000 and for cadence, t = 3.37 which is highly significant (p = 0.00 implying that cadence and distance covered in1minute walk was more with CKC exercises. Conclusion: Based on the result it is concluded that CKC exercises are effective in improving gait than OKC exercises in spastic diplegic cerebral palsy.
de Oliveira, Valéria M A; Pitangui, Ana C R; Nascimento, Vinícius Y S; da Silva, Hítalo A; Dos Passos, Muana H P; de Araújo, Rodrigo C
2017-02-01
The Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST) has been proposed as an option to assess upper limb function and stability; however, there are few studies that support the use of this test in adolescents. The purpose of the present study was to investigate the intersession reliability and agreement of three CKCUEST scores in adolescents and establish clinimetric values for this test. Test-retest reliability. Twenty-five healthy adolescents of both sexes were evaluated. The subjects performed two CKCUEST with an interval of one week between the tests. An intraclass correlation coefficient (ICC 3,3 ) two-way mixed model with a 95% interval of confidence was utilized to determine intersession reliability. A Bland-Altman graph was plotted to analyze the agreement between assessments. The presence of systematic error was evaluated by a one-sample t test. The difference between the evaluation and reevaluation was observed using a paired-sample t test. The level of significance was set at 0.05. Standard error of measurements and minimum detectable changes were calculated. The intersession reliability of the average touches score, normalized score, and power score were 0.68, 0.68 and 0.87, the standard error of measurement were 2.17, 1.35 and 6.49, and the minimal detectable change was 6.01, 3.74 and 17.98, respectively. The presence of systematic error (p test with moderate to excellent reliability when used with adolescents. The CKCUEST is a measurement with moderate to excellent reliability for adolescents. 2b.
The Life Cycle Evaluation Model of External Diseconomy of Open-loop Supply Chain
Liu, Qian; Hu, Tianjun
2017-08-01
In recent years, with the continuous deterioration of pollution, resource space is gradually narrowed, the number of waste items increased, people began to use the method of recycling on waste products to ease the pressure on the environment. This paper adopted the external diseconomy of open-loop supply chain as the research object and constructed the model by the life cycle evaluation method, comparative analysis through the case. This paper also concludes that the key to solving the problem is to realize the closed-loop supply chain and building reverse logistics system is of great significance.
Mining of Radioactive Raw Materials as an Origin of the Nuclear Fuel Chain
Directory of Open Access Journals (Sweden)
Bedřich Michálek
2007-01-01
Full Text Available The mining of radioactive raw materials may be considered as an origin of the nuclear fuel chain and thus determines the amount of radioactive wastes which have to be stored safety in the final stage of the fuel chain. The paper informs about the existing trends in mining of radioactive raw materials in the world, provides an overview of development in mining in the Czech Republic and of possibilities of future exploiting some uranium deposits. It points a possibility of non-traditional obtaining uranium from mine waters from underground uranium mines closed and flooded earlier.
Directory of Open Access Journals (Sweden)
Qingming Zou
2015-01-01
supply chain, this paper develops a revenue-sharing contract, in which the revenue share parameter is determined based on absolute deviation approach. The theoretical results are illustrated by a numerical example.
Directory of Open Access Journals (Sweden)
Huriye Yılmaz
2017-06-01
Full Text Available Collaboration plays a critical role in a globalized, rapidly changing and competitive world, as the resources of an individual company are limited to compete with the challenges of the era. Supply chain collaboration is defined as a partnership process where two or more autonomous firms work closely to plan and execute supply chain operations towards common goals and mutual benefits. Supply chain collaboration results in collaborative advantage, the strategic benefits gained over competitors through supply chain partnering, and these both increase firm performance of the partners. In this research, the effect of supply chain collaboration on firm performance has been investigated by distributing a survey to Turkish companies which have been responded by 150. The role of collaborative advantage in this relation has also been measured. The results of the research suggest that there is a positive correlation between supply chain collaboration and collaborative advantage. The results also prove that supply chain collaboration positively affects firm performance. It is also proven that the mediator role of collaborative advantage on the effect of supply chain collaboration on firm performance is statistically significant.
Wong, Chun Wa; Yasui, Kosuke
2005-01-01
The one-dimensional fall of a folded chain with one end suspended from a rigid support and a chain falling from a resting heap on a table is studied. Because their Lagrangians contain no explicit time dependence, the falling chains are conservative systems. Their equations of motion are shown to contain a term that enforces energy conservation when masses are transferred between subchains. We show that Cayley's 1857 energy nonconserving solution for a chain falling from a resting heap is inco...
Fijany, Amir
1993-01-01
In this paper, parallel O(log n) algorithms for computation of rigid multibody dynamics are developed. These parallel algorithms are derived by parallelization of new O(n) algorithms for the problem. The underlying feature of these O(n) algorithms is a drastically different strategy for decomposition of interbody force which leads to a new factorization of the mass matrix (M). Specifically, it is shown that a factorization of the inverse of the mass matrix in the form of the Schur Complement is derived as M(exp -1) = C - B(exp *)A(exp -1)B, wherein matrices C, A, and B are block tridiagonal matrices. The new O(n) algorithm is then derived as a recursive implementation of this factorization of M(exp -1). For the closed-chain systems, similar factorizations and O(n) algorithms for computation of Operational Space Mass Matrix lambda and its inverse lambda(exp -1) are also derived. It is shown that these O(n) algorithms are strictly parallel, that is, they are less efficient than other algorithms for serial computation of the problem. But, to our knowledge, they are the only known algorithms that can be parallelized and that lead to both time- and processor-optimal parallel algorithms for the problem, i.e., parallel O(log n) algorithms with O(n) processors. The developed parallel algorithms, in addition to their theoretical significance, are also practical from an implementation point of view due to their simple architectural requirements.
Scaling of quantum Fisher information close to the quantum phase transition in the XY spin chain
Energy Technology Data Exchange (ETDEWEB)
Ye, En-Jia, E-mail: yeenjia@jiangnan.edu.cn [Jiangsu Provincial Research Center of Light Industrial Optoelectronic Engineering and Technology, School of Science, Jiangnan University, Wuxi 214122 (China); Hu, Zheng-Da [Jiangsu Provincial Research Center of Light Industrial Optoelectronic Engineering and Technology, School of Science, Jiangnan University, Wuxi 214122 (China); Wu, Wei [Zhejiang Institute of Modern Physics and Physics Department, Zhejiang University, Hangzhou 310027 (China)
2016-12-01
The quantum phase transition of an XY spin chain is investigated by employing the quantum Fisher information encoded in the ground state. It is shown that the quantum Fisher information is an effective tool for characterizing the quantum criticality. The quantum Fisher information, its first and second derivatives versus the transverse field display the phenomena of sudden transition, sudden jump and divergence, respectively. Besides, the analysis of finite size scaling for the second derivative of quantum Fisher information is performed.
Kumar, Kiran; Shetty, Sharath; Krithika, M J; Cyriac, Bobby
2014-01-01
Background: The objective was to evaluate and compare the effect of Coca-Cola®, tea, Listerine® mouthwash on the force delivered by elastomeric chain in vitro. Materials and Methods: Four specimen groups (distilled water, Coca-Cola®, tea, Listerine® mouthwash) with a total sample size of 480 specimens. A specimen is described as a four link grey close elastomeric chain. Jigs, each with a series of pins set 25 mm apart, was used to hold stretched elastomeric chains at a...
Point-like bounding chains in open Gromov-Witten theory
Solomon, Jake P.; Tukachinsky, Sara B.
2016-01-01
We use $A_\\infty$ algebras to define open Gromov-Witten invariants with both boundary and interior constraints, associated to a Lagrangian submanifold $L\\subset X$ of arbitrary odd dimension. The boundary constraints are bounding chains, which are shown to behave like points. The interior constraints are arbitrary even degree classes in the cohomology of $X$ relative to $L.$ We show the invariants satisfy analogs of the axioms of closed Gromov-Witten theory. Our definition of invariants depen...
The importance of centralities in dark network value chains
Toth, Noemi; Gulyás, László; Legendi, Richard O.; Duijn, Paul; Sloot, Peter M. A.; Kampis, George
2013-09-01
This paper introduces three novel centrality measures based on the nodes' role in the operation of a joint task, i.e., their position in a criminal network value chain. For this, we consider networks where nodes have attributes describing their "capabilities" or "colors", i.e., the possible roles they may play in a value chain. A value chain here is understood as a series of tasks to be performed in a specific order, each requiring a specific capability. The first centrality notion measures how many value chain instances a given node participates in. The other two assess the costs of replacing a node in the value chain in case the given node is no longer available to perform the task. The first of them considers the direct distance (shortest path length) between the node in question and its nearest replacement, while the second evaluates the actual replacement process, assuming that preceding and following nodes in the network should each be able to find and contact the replacement. In this report, we demonstrate the properties of the new centrality measures using a few toy examples and compare them to classic centralities, such as betweenness, closeness and degree centrality. We also apply the new measures to randomly colored empirical networks. We find that the newly introduced centralities differ sufficiently from the classic measures, pointing towards different aspects of the network. Our results also pinpoint the difference between having a replacement node in the network and being able to find one. This is the reason why "introduction distance" often has a noticeable correlation with betweenness. Our studies show that projecting value chains over networks may significantly alter the nodes' perceived importance. These insights might have important implications for the way law enforcement or intelligence agencies look at the effectiveness of dark network disruption strategies over time.
Directory of Open Access Journals (Sweden)
Natalie M. Hughes
2014-01-01
Full Text Available We reviewed 153 peer-reviewed sources to provide identification of modern supply chain management techniques and exploration of supply chain modeling, to offer decision support to managers. Ultimately, the review is intended to assist member-companies of supply chains, mainly producers, improve their current management approaches, by directing them to studies that may be suitable for direct application to their supply chains and value chains for improved efficiency and profitability. We found that information on supply chain management and modeling techniques in general is available. However, few Canadian-based published studies exist regarding a demand-driven modeling approach to value/supply chain management for wood pellet production. Only three papers were found specifically on wood pellet value chain analysis. We propose that more studies should be carried out on the value chain of wood pellet manufacturing, as well as demand-driven management and modeling approaches with improved demand forecasting methods.
Slats, P.A.; Bhola, B.; Evers, J.J.M.; Dijkhuizen, G.
1995-01-01
Logistic chain modelling is very important in improving the overall performance of the total logistic chain. Logistic models provide support for a large range of applications, such as analysing bottlenecks, improving customer service, configuring new logistic chains and adapting existing chains to
A Research on Advertising Coordination Mechanism of Closed-loop Supply Chain%闭环供应链广告协调机制研究
Institute of Scientific and Technical Information of China (English)
谭建; 王先甲
2015-01-01
In order to study price decision and advertising coordinate strategy , the closed-loop supply chains are divided into two cases including the retailer recycling and manufacturer recycling .With the impact of advertising for market demand and recycling , by using the game theory, two mathematical models are established .The results show that the manufacture recycling mode is conducive to the retailer, and retailer recycling mode helps the manufacturer.Compared with retailer recovery, the share proportion of advertising costs of the retailer is smaller than from manufacturer recovery .The retailer advertising share proportion of manufacturer recovery is negatively correlated with the advertising recovery efficiency factor , and positively correlated with the advertising and marketing efficiency factor.The retailer advertising share proportion of retailer recovery has nothing to do with the cost of advertising marketing efficiency factor , and recovery efficiency factor .At last the related conclusion is proved through simulation .This research provides coordination strategies under different recycling modes with closed-loop supply chain advertising marketing and recovery efficiency varying .%为了研究闭环供应链中零售商回收与制造商回收时两种情形下价格决策与广告协调策略，在广告既能影响市场需求又能影响回收率的条件下，运用博弈论分别建立制造商回收与零售商回收时的广告分摊协调策略数学模型，结果表明制造商回收模式有利于零售商，零售商回收模式有利于制造商。零售商所分摊的广告费用比例在制造回收时小。制造商回收时零售商所分摊的广告费用比例与广告回收效率因子负相关，与广告营销效率因子正相关。零售商将回收时零售商所分摊的广告费用比例与回收效率因子、营销效率因子无关。最后通过仿真证明了相关结论。本文的研究为闭环供应链在不同回收模式下广告回收效率与营销效率的变化时提供相应的协调策略。
Integrable open spin chain in Super Yang-Mills and the plane-wave/SYM duality
International Nuclear Information System (INIS)
Chen Bin; Wang Xiaojun; Wu Yongshi
2004-01-01
We investigate the integrable structures in an N = 2 superconfomal Sp(N) Yang-Mills theory with matter, which is dual to an open+closed string system. We restrict ourselves to the BMN operators that correspond to free string states. In the closed string sector, an integrable structure is inherited from its parent theory, N = 4 SYM. For the open string sector, the planar one-loop mixing matrix for gauge invariant holomorphic operators is identified with the Hamiltonian of an integrable SU(3) open spin chain. Using the K-matrix formalism we identify the integrable open-chain boundary conditions that correspond to string boundary conditions. The solutions to the algebraic Bethe ansatz equations (ABAE) with a few impurities are shown to recover the anomalous dimensions that exactly match the spectrum of free open string in the plane-wave background. We also discuss the properties of the solutions of ABAE beyond the BMN regime. (author)
A fast direct sampling algorithm for equilateral closed polygons
International Nuclear Information System (INIS)
Cantarella, Jason; Duplantier, Bertrand; Shonkwiler, Clayton; Uehara, Erica
2016-01-01
Sampling equilateral closed polygons is of interest in the statistical study of ring polymers. Over the past 30 years, previous authors have proposed a variety of simple Markov chain algorithms (but have not been able to show that they converge to the correct probability distribution) and complicated direct samplers (which require extended-precision arithmetic to evaluate numerically unstable polynomials). We present a simple direct sampler which is fast and numerically stable, and analyze its runtime using a new formula for the volume of equilateral polygon space as a Dirichlet-type integral. (paper)
Belyaev, Alexander; Sukhanov, Alexander; Tsvetkov, Alexander
2016-03-01
This article addresses the problem in which a chain falls from a glass from some height. This phenomenon demonstrates a paradoxical rise of the chain over the glass. To explain this effect, an initial hypothesis and an appropriate theory are proposed for calculating the steady fall parameters of the chain. For this purpose, the modified Cayley's problem of falling chain given its rise due to the centrifugal force of upward inertia is solved. Results show that the lift caused by an increase in linear density at the part of chain where it is being bent (the upper part) is due to the convergence of the chain balls to one another. The experiments confirm the obtained estimates of the lifting chain.
A novel approach for inventory problem in the pharmaceutical supply chain.
Candan, Gökçe; Yazgan, Harun Reşit
2016-02-24
In pharmaceutical enterprises, keeping up with global market conditions is possible with properly selected supply chain management policies. Generally; demand-driven classical supply chain model is used in the pharmaceutical industry. In this study, a new mathematical model is developed to solve an inventory problem in the pharmaceutical supply chain. Unlike the studies in literature, the "shelf life and product transition times" constraints are considered, simultaneously, first time in the pharmaceutical production inventory problem. The problem is formulated as a mixed-integer linear programming (MILP) model with a hybrid time representation. The objective is to maximize total net profit. Effectiveness of the proposed model is illustrated considering a classical and a vendor managed inventory (VMI) supply chain on an experimental study. To show the effectiveness of the model, an experimental study is performed; which contains 2 different supply chain policy (Classical and VMI), 24 and 30 months planning horizon, 10 and 15 different cephalosporin products. Finally the mathematical model is compared to another model in literature and the results show that proposed model is superior. This study suggest a novel approach for solving pharmaceutical inventory problem. The developed model is maximizing total net profit while determining optimal production plan under shelf life and product transition constraints in the pharmaceutical industry. And we believe that the proposed model is much more closed to real life unlike the other studies in literature.
Numerical study of two disks settling in an Oldroyd-B fluid: From periodic interaction to chaining
Pan, Tsorng-Whay; Glowinski, Roland
2017-12-01
In this article, we present a numerical study of the dynamics of two disks sedimenting in a narrow vertical channel filled with an Oldroyd-B fluid. Two kinds of particle dynamics are observed: (i) a periodic interaction between the two disks, and (ii) the formation of a two-disk chain. For the periodic interaction of the two disks, two different motions are observed: (a) the two disks stay far apart and interact periodically, and (b) the two disks interact closely and then far apart in a periodic way, like the drafting, kissing, and tumbling of two disks sedimenting in a Newtonian fluid, due to a weak elastic force. Concerning the formation of a two-disk chain occurring at higher values of the elasticity number, either a tilted chain or a vertical chain is observed. Our simulations show that, as expected, the values of the elasticity and Mach numbers are the determining factors concerning the particle chain formation and its orientation.
Learning-based position control of a closed-kinematic chain robot end-effector
Nguyen, Charles C.; Zhou, Zhen-Lei
1990-01-01
A trajectory control scheme whose design is based on learning theory, for a six-degree-of-freedom (DOF) robot end-effector built to study robotic assembly of NASA hardwares in space is presented. The control scheme consists of two control systems: the feedback control system and the learning control system. The feedback control system is designed using the concept of linearization about a selected operating point, and the method of pole placement so that the closed-loop linearized system is stabilized. The learning control scheme consisting of PD-type learning controllers, provides additional inputs to improve the end-effector performance after each trial. Experimental studies performed on a 2 DOF end-effector built at CUA, for three tracking cases show that actual trajectories approach desired trajectories as the number of trials increases. The tracking errors are substantially reduced after only five trials.
Directory of Open Access Journals (Sweden)
Aletta S. Tolmay
2015-10-01
Full Text Available Background: The automotive industry is characterised by a network of long term collaborative agreements between component suppliers and assemblers. For collaboration to be successful trust between the supply chain partners is vital. Although many variables influence the efficiency of collaborative relationships, the human behaviour issues related to culture and trust are often much more difficult to solve. Trust is singled out in this article as a contributor to value in the supply chain relationships. Increased trust leads to more confidence resulting in better collaboration. Objectives: The purpose of the study was to explore collaborative relationships between first and second tier suppliers (component manufacturers in automotive supply chains in South Africa and the role of trust in the relationship value. Method: This quantitative study had been conducted amongst members of the National Association for Automobile Component and Allied Manufacturers of South Africa (NAACAM, who are suppliers to the large automotive assemblers. The research utilised closed ended questions to obtain the perceptions of managers in automotive component manufacture regarding trust and relationship value with their best suppliers. Results: With a linear regression model it was found that there is a high degree of trust in the collaborative relationships between first and second tier suppliers of components in the automotive industry in South Africa. Conclusion: The automotive industry is one of the most successful industries in South Africa. They compete globally and apply best practices, particularly those in supply chain management. The industry is characterised by networks of collaborative relationships on different levels. These relationships seem to be successful as they are based on trust.
What Can Healthcare Supply Chains Learn from Consumer-Product Supply Chains?
Schwarz, Leroy B.
2008-01-01
A Framework for Thinking About Supply-Chain Management: “The IDIB Portfolio” (Information, Decision-making, Implementation, Buffer system) Describe Supply-Chains for Consumer Products Before “Wal-Mart” Describe Supply-Chains for Consumer Products After “Wal-Mart” Describe Stylized Supply Chain for Healthcare Products
Markov Chain Model with Catastrophe to Determine Mean Time to Default of Credit Risky Assets
Dharmaraja, Selvamuthu; Pasricha, Puneet; Tardelli, Paola
2017-11-01
This article deals with the problem of probabilistic prediction of the time distance to default for a firm. To model the credit risk, the dynamics of an asset is described as a function of a homogeneous discrete time Markov chain subject to a catastrophe, the default. The behaviour of the Markov chain is investigated and the mean time to the default is expressed in a closed form. The methodology to estimate the parameters is given. Numerical results are provided to illustrate the applicability of the proposed model on real data and their analysis is discussed.
Baxter Q-operator and separation of variables for the open SL(2, R) spin chain
International Nuclear Information System (INIS)
Derkachov, Sergey E.; Korchemsky, Gregory P.; Manashov, Alexander N.
2003-01-01
We construct the Baxter Q-operator and the representation of the Separated Variables (SoV) for the homogeneous open SL(2, R) spin chain. Applying the diagrammatical approach, we calculate Sklyanin's integration measure in the separated variables and obtain the solution to the spectral problem for the model in terms of the eigenvalues of the Q-operator. We show that the transition kernel to the SoV representation is factorized into the product of certain operators each depending on a single separated variable. As a consequence, it has a universal pyramid-like form that has been already observed for vari- ous quantum integrable models such as periodic Toda chain, closed SL(2, R) and SL(2, C) spin chains. (author)
Multi-chain Markov chain Monte Carlo methods for computationally expensive models
Huang, M.; Ray, J.; Ren, H.; Hou, Z.; Bao, J.
2017-12-01
Markov chain Monte Carlo (MCMC) methods are used to infer model parameters from observational data. The parameters are inferred as probability densities, thus capturing estimation error due to sparsity of the data, and the shortcomings of the model. Multiple communicating chains executing the MCMC method have the potential to explore the parameter space better, and conceivably accelerate the convergence to the final distribution. We present results from tests conducted with the multi-chain method to show how the acceleration occurs i.e., for loose convergence tolerances, the multiple chains do not make much of a difference. The ensemble of chains also seems to have the ability to accelerate the convergence of a few chains that might start from suboptimal starting points. Finally, we show the performance of the chains in the estimation of O(10) parameters using computationally expensive forward models such as the Community Land Model, where the sampling burden is distributed over multiple chains.
Functional methods for the solution of one-dimensional quantum systems
International Nuclear Information System (INIS)
Wirth, Tobias
2010-01-01
Subject of this work are integrable spin chains with general boundary conditions. In the framework of the Quantum Inverse Scattering Method Sklyanin has shown how to construct a family of commuting operators (transfer matrix) containing the hamiltonian of the XXX or XXZ spin chain with general boundary fields. Key ingredient is the underlying algebraic structure which is a combination of the Yang-Baxter algebra, using the known R-matrix representations, and a so-called Reflection algebra. The latter includes fields of arbitrary strength and direction acting on the first and last position of the chain. This setup is solvable via algebraic Bethe ansatz in the case of diagonal boundaries, i.e. the fields are parallel to each other and in the case of the XXZ model parallel to the distinguished direction. Kitanine et. al. have managed to express local operators in terms of the non-local elements of the underlying algebraic structure in the case of half-infinite chain length hence establishing a possible approach to evaluate expectation values of physical observables. Their results are picked up in this work and generalized to spin chains of arbitrary (including finite) lengths using non-linear integral equations for the lowest lying state with zero magnetization. In the case of non-diagonal boundary fields the lack of a reference state or pseudo vacuum prohibits the solution by algebraic Bethe ansatz. The method of separation of variables proposed by Sklyanin is not constrained in that sense and will be applied to this situation. In this approach for the XXX spin chain no restrictions to the boundary parameters are needed. The result is a TQ-equation on finite discrete set of points and the eigenvalues of the transfer matrix are obtainable from this finite difference equation. As the underlying algebraic structure is independent of the representation, the analysis for the XXX spin chain can be extended to a spin-boson model. Using a known representation of the algebra
Hughes, Natalie M.; Shahi, Chander; Pulkki, Reino
2014-01-01
We reviewed 153 peer-reviewed sources to provide identification of modern supply chain management techniques and exploration of supply chain modeling, to offer decision support to managers. Ultimately, the review is intended to assist member-companies of supply chains, mainly producers, improve their current management approaches, by directing them to studies that may be suitable for direct application to their supply chains and value chains for improved efficiency and profitability. We found...
Helimagnetism and weak ferromagnetism in edge-shared chain cuprates
International Nuclear Information System (INIS)
Drechsler, S.-L.; Richter, J.; Kuzian, R.; Malek, J.; Tristan, N.; Buechner, B.; Moskvin, A.S.; Gippius, A.A.; Vasiliev, A.; Volkova, O.; Prokofiev, A.; Rakoto, H.; Broto, J.-M.; Schnelle, W.; Schmitt, M.; Ormeci, A.; Loison, C.; Rosner, H.
2007-01-01
The present understanding of a novel growing class of chain cuprates with intriguing magnetic properties is reviewed. Among them, several undoped edge-shared CuO 2 chain compounds show at low temperature a clear tendency to helicoidal magnetical ordering with acute pitch angles and sometimes also to weak ferromagnetism. Our analysis is based on the isotropic 1D frustrated J 1 -J 2 Heisenberg model with ferromagnetic (FM) 1st neighbor and antiferromagnetic 2nd neighbor exchange. The achieved assignment is supported by microscopic calculations of the electronic and magnetic structure. We consider Na(Li)Cu 2 O 2 , LiVCuO 4 as the best studied helimagnets, Li 2 ZrCuO 4 and other systems close to a FM quantum critical point, as well as Li 2 CuO 2 with FM inchain ordering. The interplay of frustrated inchain couplings, anisotropy and interchain exchange is discussed
Evolution of massive close binaries and formation of neutron stars and black holes
International Nuclear Information System (INIS)
Massevitch, A.G.; Tutukov, A.V.; Yungelson, L.R.
1976-01-01
Main results of computations of evolution for massive close binaries (10 M(Sun)+9.4 M(Sun), 16 M(Sun)+15 M(Sun), 32 M(Sun)+30 M(Sun), 64 M(Sun)+60 M(Sun)) up to oxygen exhaustion in the core are described. Mass exchange starting in core hydrogen, shell hydrogen and core helium burning stages was studied. Computations were performed assuming both the Ledoux and Schwarzschild stability criteria for semiconvection. The influence of UFI-neutrino emission on evolution of close binaries was investigated. The results obtained allow to outline the following evolutionary chain: two detached Main-Sequence stars - mass exchange - Wolf-Rayet star or blue supergiant plus main sequence star - explosion of the initially more massive star appearing as a supernova event - collapsed or neutron star plus Main-Sequence star, that may be observed as a 'runaway star' - mass exchange leading to X-rays emission - collapsed or neutron star plus WR-star or blue supergiant - second explosion of supernova that preferentially disrupts the system and gives birth to two single high spatial velocity pulsars. Numerical estimates concerning the number and properties of WR-stars, pulsars and X-ray sources are presented. The results are in favour of the existence of UFI-neutrino and of the Ledoux criterion for describing semiconvection. Properties of several well-known X-ray sources and the binary pulsar are discussed on base of evolutionary chain of close binaries. (Auth.)
Directory of Open Access Journals (Sweden)
Xiaolu Zhang
2018-01-01
Full Text Available The aim of this study is to develop a new closeness degree-based hesitant trapezoidal fuzzy (HTrF multicriteria decision making (MCDM approach for identifying the most appropriate green suppliers in food supply chain involving uncertain qualitative evaluation information. The uniqueness of the proposed HTrF MCDM method is the consideration of uncertain qualitative information represented by flexible linguistic expressions based on HTrF values and the construction of compromise solution with the revised closeness degree. The revised closeness degree can make sure that the most appropriate solution has the shortest distance from the HTrF positive ideal solution and the farthest distance from the HTrF negative ideal solution, simultaneously. This proposed HTrF MCDM technique not only offers a simple and efficient decision support tool to aid the food firms for identifying the optimal suppliers in food supply chain but also can enable the managers of food firms to better understand the complete evaluation and decision processes. In addition, this study provides a novel defuzzification technique to manage the HTrF weights values of main-criteria and subcriteria, respectively.
Abdulla, Parosh Aziz; Henda, Noomene Ben; Mayr, Richard
2007-01-01
We consider qualitative and quantitative verification problems for infinite-state Markov chains. We call a Markov chain decisive w.r.t. a given set of target states F if it almost certainly eventually reaches either F or a state from which F can no longer be reached. While all finite Markov chains are trivially decisive (for every set F), this also holds for many classes of infinite Markov chains. Infinite Markov chains which contain a finite attractor are decisive w.r.t. every set F. In part...
Magnetization plateaux and jumps in frustrated four-leg spin tubes in magnetic fields
International Nuclear Information System (INIS)
Rosales, H D; Arlego, M; Albarracín, F A Gómez
2014-01-01
We study the ground state phase diagram of a frustrated spin-1/2 four-leg tube in an external magnetic field. We explore the parameter space of this model in the regime of all-antiferromagnetic exchange couplings by means of three different approaches: density matrix renormalization group (DMRG), a low-energy effective Hamiltonian (LEH) and a Hartree variational approach (HVA). We find that in the limit of weakly interacting plaquettes, singlet and triplet states play an important role in the formation of magnetization plateaux. We study the transition regions numerically and analytically, and find that they are described, at first order in a strong- coupling expansion, by an XXZ spin-1/2 chain in a magnetic field. These results are consistent with the DMRG and HVA calculations
Unconventional phase transitions in a constrained single polymer chain
International Nuclear Information System (INIS)
Klushin, L I; Skvortsov, A M
2011-01-01
Phase transitions were recognized among the most fascinating phenomena in physics. Exactly solved models are especially important in the theory of phase transitions. A number of exactly solved models of phase transitions in a single polymer chain are discussed in this review. These are three models demonstrating the second order phase transitions with some unusual features: two-dimensional model of β-structure formation, the model of coil–globule transition and adsorption of a polymer chain grafted on the solid surface. We also discuss models with first order phase transitions in a single macromolecule which admit not only exact analytical solutions for the partition function with explicit finite-size effects but also the non-equilibrium free energy as a function of the order parameter (Landau function) in closed analytical form. One of them is a model of mechanical desorption of a macromolecule, which demonstrates an unusual first order phase transition with phase coexistence within a single chain. Features of first and second order transitions become mixed here due to phase coexistence which is not accompanied by additional interfacial free energy. Apart from that, there exist several single-chain models belonging to the same class (adsorption of a polymer chain tethered near the solid surface or liquid–liquid interface, and escape transition upon compressing a polymer between small pistons) that represent examples of a highly unconventional first order phase transition with several inter-related unusual features: no simultaneous phase coexistence, and hence no phase boundary, non-concave thermodynamic potential and non-equivalence of conjugate ensembles. An analysis of complex zeros of partition functions upon approaching the thermodynamic limit is presented for models with and without phase coexistence. (topical review)
Low latitude ionosphere-thermosphere dynamics studies with inosonde chain in Southeast Asia
Directory of Open Access Journals (Sweden)
T. Maruyama
2007-07-01
Full Text Available An ionosonde network consisting of a meridional chain and an equatorial pair was established in the Southeast Asian area. Three of four ionosondes are along the magnetic meridian of 100° E; two are close to the magnetic conjugate points in Northern Thailand and West Sumatra, Indonesia, and the other is near the magnetic equator in the Malay Peninsula, Thailand. The fourth ionosonde is also near the magnetic equator in Vietnam but separated by about 6.3° towards east from the meridional chain. For a preliminary data analysis, nighttime ionospheric height variations at the three stations of the meridional chain were examined. The results demonstrate that the coordination of the network has a great potential for studying ionosphere/thermosphere dynamics. Through the assistance of model calculations, thermospheric neutral winds were inferred and compared with the HWM93 empirical thermospheric wind model. Higher-order wind variations that are not represented in the empirical model were found.
Feng, Wei; Wang, Zhigang; Zhang, Wenke
2017-02-28
Understanding the relationship between polymer chain conformation as well as the chain composition within the single crystal and the mechanical properties of the corresponding single polymer chain will facilitate the rational design of high performance polymer materials. Here three model systems of polymer single crystals, namely poly(ethylene oxide) (PEO), polyethylene (PE), and nylon-66 (PA66) have been chosen to study the effects of chain conformation, helical (PEO) versus planar zigzag conformation (PE, PA66), and chain composition (PE versus PA66) on the mechanical properties of a single polymer chain. To do that, steered molecular dynamics simulations were performed on those polymer single crystals by pulling individual polymer chains out of the crystals. Our results show that the patterns of force-extension curve as well as the chain moving mode are closely related to the conformation of the polymer chain in the single crystal. In addition, hydrogen bonds can enhance greatly the force required to stretch the polymer chain out of the single crystal. The dynamic breaking and reformation of multivalent hydrogen bonds have been observed for the first time in PA66 at the single molecule level.
Enlarged symmetry algebras of spin chains, loop models, and S-matrices
International Nuclear Information System (INIS)
Read, N.; Saleur, H.
2007-01-01
The symmetry algebras of certain families of quantum spin chains are considered in detail. The simplest examples possess m states per site (m>=2), with nearest-neighbor interactions with U(m) symmetry, under which the sites transform alternately along the chain in the fundamental m and its conjugate representation m-bar. We find that these spin chains, even with arbitrary coefficients of these interactions, have a symmetry algebra A m much larger than U(m), which implies that the energy eigenstates fall into sectors that for open chains (i.e., free boundary conditions) can be labeled by j=0,1,...,L, for the 2L-site chain such that the degeneracies of all eigenvalues in the jth sector are generically the same and increase rapidly with j. For large j, these degeneracies are much larger than those that would be expected from the U(m) symmetry alone. The enlarged symmetry algebra A m (2L) consists of operators that commute in this space of states with the Temperley-Lieb algebra that is generated by the set of nearest-neighbor interaction terms; A m (2L) is not a Yangian. There are similar results for supersymmetric chains with gl(m+n|n) symmetry of nearest-neighbor interactions, and a richer representation structure for closed chains (i.e., periodic boundary conditions). The symmetries also apply to the loop models that can be obtained from the spin chains in a spacetime or transfer matrix picture. In the loop language, the symmetries arise because the loops cannot cross. We further define tensor products of representations (for the open chains) by joining chains end to end. The fusion rules for decomposing the tensor product of representations labeled j 1 and j 2 take the same form as the Clebsch-Gordan series for SU(2). This and other structures turn the symmetry algebra A m into a ribbon Hopf algebra, and we show that this is 'Morita equivalent' to the quantum group U q (sl 2 ) for m=q+q -1 . The open-chain results are extended to the cases vertical bar m vertical
Requirements of supply chain management in differentiating European pork chains.
Trienekens, Jacques; Wognum, Nel
2013-11-01
This paper summarizes results obtained by research into pork chain management in the EU Integrated Project Q-Porkchains. Changing demands for intrinsic and extrinsic quality attributes of pork products impact the way supply chain management should be organized from the farmer down to the consumer. The paper shows the importance of Quality Management Systems for integrating supply chains and enhancing consumer confidence. The paper also presents innovations in information system integration for aligning information exchange in the supply chain and logistics concepts based on innovative measurement technologies at the slaughterhouse stage. In the final section research challenges towards sustainable pork supply chains satisfying current consumer demands are presented. Copyright © 2013 Elsevier Ltd. All rights reserved.
Canonical Correlation Analysis Between Supply Chain Quality Management And Competitive Advantages
Directory of Open Access Journals (Sweden)
Chaghooshi Ahmad Jafarnejad
2015-06-01
Full Text Available Competitive environment of today’s organizations, more than ever, is extensive, and the major concern for managers is to preserve and promote the sustainable competitive advantage. Companies have an obligation to improve their product quality and have extensive and close cooperation with other companies involved in the supply chain of products. Supply chain quality management (SCQM is a systematic approach to improve the performance that integrates supply chain partners and uses the opportunity in the best way, establish linkages between upstream and downstream flows, and investigate on creating value and satisfaction of intermediaries and final customers. Furthermore, achieving competitive advantages enables an organization to create a remarkable position in market and differentiate itself from competitors. This paper aims to understand the relationships between SCQM and competitive advantage. Sixty-eight experts of 25 companies in Sahami Alyaf (SA supply chain has been participated in this research. The research method used for this article is descriptive correlation. To assess the relationships between the criteria, canonical correlation analysis was used. The result shows that the SCQM and competitive advantages have a meaningful relationship. It also shows that most important variable in the linear combination of SCQM and competitive advantages are “customer focus and quality,” respectively.
Adjoint sensitivity analysis of dynamic reliability models based on Markov chains - I: Theory
International Nuclear Information System (INIS)
Cacuci, D. G.; Cacuci, D. G.; Ionescu-Bujor, M.
2008-01-01
The development of the adjoint sensitivity analysis procedure (ASAP) for generic dynamic reliability models based on Markov chains is presented, together with applications of this procedure to the analysis of several systems of increasing complexity. The general theory is presented in Part I of this work and is accompanied by a paradigm application to the dynamic reliability analysis of a simple binary component, namely a pump functioning on an 'up/down' cycle until it fails irreparably. This paradigm example admits a closed form analytical solution, which permits a clear illustration of the main characteristics of the ASAP for Markov chains. In particular, it is shown that the ASAP for Markov chains presents outstanding computational advantages over other procedures currently in use for sensitivity and uncertainty analysis of the dynamic reliability of large-scale systems. This conclusion is further underscored by the large-scale applications presented in Part II. (authors)
Adjoint sensitivity analysis of dynamic reliability models based on Markov chains - I: Theory
Energy Technology Data Exchange (ETDEWEB)
Cacuci, D. G. [Commiss Energy Atom, Direct Energy Nucl, Saclay, (France); Cacuci, D. G. [Univ Karlsruhe, Inst Nucl Technol and Reactor Safety, D-76021 Karlsruhe, (Germany); Ionescu-Bujor, M. [Forschungszentrum Karlsruhe, Fus Program, D-76021 Karlsruhe, (Germany)
2008-07-01
The development of the adjoint sensitivity analysis procedure (ASAP) for generic dynamic reliability models based on Markov chains is presented, together with applications of this procedure to the analysis of several systems of increasing complexity. The general theory is presented in Part I of this work and is accompanied by a paradigm application to the dynamic reliability analysis of a simple binary component, namely a pump functioning on an 'up/down' cycle until it fails irreparably. This paradigm example admits a closed form analytical solution, which permits a clear illustration of the main characteristics of the ASAP for Markov chains. In particular, it is shown that the ASAP for Markov chains presents outstanding computational advantages over other procedures currently in use for sensitivity and uncertainty analysis of the dynamic reliability of large-scale systems. This conclusion is further underscored by the large-scale applications presented in Part II. (authors)
Sustainable Supply Chain Design
DEFF Research Database (Denmark)
Bals, Lydia; Tate, Wendy
A significant conceptual and practical challenge is how to integrate triple bottom line (TBL; including economic, social and environmental) sustainability into global supply chains. Although this integration is necessary to slow down global resource depletion, understanding is limited of how...... to implement TBL goals across the supply chain. In supply chain design, the classic economic perspective still dominates, although the idea of the TBL is more widely disseminated. The purpose of this research is to add to the sustainable supply chain management literature (SSCM) research agenda...... by incorporating the physical chain, and the (information and financial) support chains into supply chain design. This manuscript tackles issues of what the chains are designed for and how they are designed structurally. Four sustainable businesses are used as illustrative case examples of innovative supply chain...
A new fuzzy mathematical model for green supply chain network design
Directory of Open Access Journals (Sweden)
Mohsen Sadegh Amalnick
2017-01-01
Full Text Available The environmental changes caused by industrial activities have spurred a significant interest in designing supply chain networks by considering environmental issues such as CO2 emission. The pivotal role of taking uncertainty and risk into account in closed-loop supply chain networks has induced numerous researchers and practitioners to develop appropriate decision making tools to cope with these issues in such networks. To design a supply chain regarding environmental impacts under uncertainty of the input data and to cope with the operational risks, this paper proposes a multi objective possibilistic optimization model. The proposed model minimizes traditional costs such as cost of products shipment, purchasing machines and so on, as well as minimizing the environmental impact, and as a results strikes a balance between the two objective functions. Furthermore, in order to solve the proposed multi objective fuzzy mathematical programming model, an interactive fuzzy solution approach is applied. Numerical experiments are used to prove the applicability and feasibility of the developed possibilistic programming model and the usefulness of the applied hybrid solution approach.
Zhang, Shuangshuang; Qi, Shuanhu; Klushin, Leonid I.; Skvortsov, Alexander M.; Yan, Dadong; Schmid, Friederike
2018-01-01
We use Brownian dynamics simulations and analytical theory to compare two prominent types of single molecule transitions. One is the adsorption transition of a loop (a chain with two ends bound to an attractive substrate) driven by an attraction parameter ɛ and the other is the loop-stretch transition in a chain with one end attached to a repulsive substrate, driven by an external end-force F applied to the free end. Specifically, we compare the behavior of the respective order parameters of the transitions, i.e., the mean number of surface contacts in the case of the adsorption transition and the mean position of the chain end in the case of the loop-stretch transition. Close to the transition points, both the static behavior and the dynamic behavior of chains with different length N are very well described by a scaling ansatz with the scaling parameters (ɛ - ɛ*)Nϕ (adsorption transition) and (F - F*)Nν (loop-stretch transition), respectively, where ϕ is the crossover exponent of the adsorption transition and ν is the Flory exponent. We show that both the loop-stretch and the loop adsorption transitions provide an exceptional opportunity to construct explicit analytical expressions for the crossover functions which perfectly describe all simulation results on static properties in the finite-size scaling regime. Explicit crossover functions are based on the ansatz for the analytical form of the order parameter distributions at the respective transition points. In contrast to the close similarity in equilibrium static behavior, the dynamic relaxation at the two transitions shows qualitative differences, especially in the strongly ordered regimes. This is attributed to the fact that the surface contact dynamics in a strongly adsorbed chain is governed by local processes, whereas the end height relaxation of a strongly stretched chain involves the full spectrum of Rouse modes.
DEFF Research Database (Denmark)
Larsen, Samuel Brüning; Masi, Donato; Jacobsen, Peter
2017-01-01
The ongoing transition to a Circular Economy is changing the shape of Supply Chains. They are becoming more ‘Closed-Loop’, combining forward and reverse flows of products and materials. Reverse Supply Chains (RSCs), originally considered as a solution for handling waste or recovering residual value...... seven case studies, focusing on original equipment manufacturers (OEMs), show how the RSC can play a strategic, tactical, or operational role for the firm. The paper applies for the first time the concept of strategic alignment to the RSC and practitioners can use the proposed framework to analyse...
Campbell, J; Lowe, J; Walz, S; Ezzell, J
1993-01-01
We developed a 4-h nested polymerase chain reaction assay that detected a region of the plasminogen activator gene of Yersinia pestis in 100% of 43 Y. pestis strains isolated from humans, rats, and fleas yet was unreactive with the closely related species Yersinia enterocolitica and Yersinia pseudotuberculosis.
Supply Chain Management og Supply Chain costing
DEFF Research Database (Denmark)
Nielsen, Steen; Mortensen, Ole
2002-01-01
Formålet med denne artikel er at belyse de muligheder som ligger i at integrere virksomhedens økonomiske styring med begrebet Supply Chain Management (SCM). Dette søges belyst ved først at beskrive den teoretiske ramme, hvori SCM indgår. Herefter analyseres begrebet Supply Chain Costing (SCC) som...... Århus. Et resultat er, at via begrebet Supply Chain Costing skabes der mulighed for at måle logistikkædens aktiviteter i kr./øre. Anvendelsen af denne information har også strategisk betydning for at kunne vælge kunde og leverandør. Ved hjælp af integrationen skabes der også helt nye mulighed...
Directory of Open Access Journals (Sweden)
Rui Zhao
2018-03-01
Full Text Available This study redesigns the supply chain of agricultural products in southwest China under the Belt and Road Initiative to improve its eco-efficiency by considering the associated agro-wastes flowing into bioenergy enterprise for energy production. Two scenarios are created, in which the first assumes that all waste flows into the enterprise, whereas the second only considers the inflow of agro-waste produced by farmers and the wholesale market. A system dynamics simulation is conducted by using carbon emissions per product as an indicator to obtain the optimal scenario for managerial practice and design an incentivizing mechanism to drive supply chain operations. A case study is provided to demonstrate application of the system dynamics. Finally, the limitations of the study are discussed to lay the foundation for further improvement.
The Use of Supply Chains and Supply Chain Management in the ...
African Journals Online (AJOL)
Dr Peter Schmitz
supply chain management to guide the production of maps. Supply chain management can ... Distribution and logistics. Product flow. Information flow and Money. The Firm. Data from supplier(s) ..... In Global Supply Chains: Developing Skills ...
Tension in the tie-down chains of a shipping container for hazardous material
International Nuclear Information System (INIS)
Lo, T.Y.
1995-01-01
Chains are frequently used to tie the shipping containers of hazardous material to a truck bed. The tie-down system is nonlinear when the container is subjected to a triaxial force during transit. It is nonlinear because chains cannot carry compressive force, and the base of the container may partially lift off from the truck bed. A method was developed to calculate the amount of tension in the chains. This methodology includes three assumptions: (1) No friction exists between the container and the truck bed; (2) The container and the truck bed are rigid; and (3) All chains are properly tightened (i.e., no slacks) during preparation for shipment. The methodology employs an iterative process of a linear tie-down system. This linear system is derived from the nonlinear system with two additional assumptions: (a) All chains can carry compression as well as tension; and (b) There is a point contact between the container and the truck bed. This linear system has a closed-form solution. After the first solution of the linear system is obtained, the unreasonable, or physically impossible, rotational degree of freedom of the container and the chains with compressive force are eliminated in the follow-up iterative calculations using the same linear system. Unreasonable rotation is detected when the results indicate a rotation of the container into the truck bed. Zero rotational value is assigned to this degree of freedom in the follow-up iterations. For chains under compression, the chain length is replaced with a fictitiously large value because a long chain carries essentially no load. This process usually needs only two or three iterations and can easily be carried out in a spread sheet using such programs as Microsoft Excel or LOTUS 123
To Cooperate or Not? An Analysis of Complementary Product Pricing in Green Supply Chain
Directory of Open Access Journals (Sweden)
Jie Wei
2018-05-01
Full Text Available This paper investigates the green supply chain pricing problem when two manufacturers sell complementary products to one retailer. Considering the manufacturers’ cooperation or noncooperation strategies, we first give the centralized pricing model as a benchmark. According to market power among the supply chain, we analyze two types of supply chains: supplier-led type where the green driving factor comes from the suppliers and retailer-led type where the core member retailer leads the green supply chain. We then give two decentralized pricing models through considering strategic cooperation between two manufacturers and different structures. Corresponding closed-form expressions for equilibrium pricing strategies are established. Finally, many valuable managerial results are acquired through comparing the profits and equilibrium decisions of these models. Our paper shows that consumers are indifferent as to who is the leader of the two echelons when the manufacturers adopt non-cooperative action; the two complementary products get the same optimal wholesale/retail prices, maximum retail margins, and maximum demands regardless of the manufacturers’ cooperation or noncooperation strategies.
The sanitation value chain: its concept and new research collaboration project
Funamizu, N.
2017-03-01
Sanitation is essential for promoting health, preventing environment pollution, conserving ecosystem, and recovering and recycling resources. Therefore, it can be said that sanitation is closely related to such current global issues as poverty, urban slum, conservation of ecosystem, and resources management. Namely, the question, “How can we handle the waste from 10 billion people in future?” is a global environmental problem to be solved. In developing world, population is growing rapidly especially in urban slums and they have still high under 5 mortality and poverty issues. It also reported that 2.4 billion people are still using unimproved sanitation facilities, including 946 million people who are still practicing open defecation in 2015 (UN, 2015). On the other hand, depopulation and aging are progressing especially in rural area of developed world. Based on the above mentioned background, new research project on sanitation value chain has started. This is a collaboration project with LIPI, RIHN (Research Institute of Humanity and Nature, Kyoto) and HU (Hokkaido University). The concept of the sanitation value chain and the brief summary of the project are discussed in the keynote presentation. The concept of sanitation value chain proposed in the project : The project is proposing new concept, Sanitation Value Chain, which has the following basic policies: 1) Put values of people/and community in the centre of discussion, and prepare sanitation system to drive this value chain; 2) Design the sanitation system by focusing on incentive for individual users and community; 3) Recognize a sanitation system as an integrated system with social and technical systems; 4) Design the sanitation system by making a good matching between social characteristics and prerequisites of the technologies. The goals of the research are 1) To propose the Sanitation Value Chain as a common solution for both developing and developed countries, 2) To show the validity of the
Architectures for Green-Field Supply Chain Integration: Supply Chain Integration Design
Radanliev, Petar
2015-01-01
This paper applied case study research to design architectures for green-field supply chain integration. The integration design is based on a case study of a supply chain integration of 5 companies, operating in different, but supply chain complimenting industry sectors. The case study research is applied to design and validate the architectures in a real world scenario. The supply\\ud chain integration architectures enable the conversion of individual into integrated strategies. The architect...
Pengukuran Kinerja Supply Chain Dengan Pendekatan Supply Chain Operation References (SCOR)
Rizki Wahyuniardi; Moh. Syarwani; Ryan Anggani
2017-01-01
PT. Brodo Ganesha Indonesia is a national company engaged in manufacturing with the production of leather shoes. The company has many stakeholders and it is difficult to manage its supply chain, thereby affecting the effectiveness and efficiency of the company's supply chains. The research was conducted to measure the performance of supply chain by using Supply Chain Operation References (SCOR) approach. The initial hierarchy model of performance measurement is tailored to the company's condi...
The role of supply chain collaboration in supply chain risk mitigation
Chen, Jie
2017-01-01
In the last two decades, supply chain operations have changed drastically. Globalization of the market, shortened product life cycle, global outsourcing and offshoring, and increasing complexity of the supply base has resulted in modern supply chains becoming more vulnerable than ever. There are also more frequent natural or man-made disasters which disrupt the supply chain operations. All these have led to higher exposure of risks of supply chains and the failure to manage the...
Logistics competencies of polish companies as a factor of development of virtual supply chains
Directory of Open Access Journals (Sweden)
2010-03-01
Full Text Available Problems of virtual organizations have not been well elaborated yet. There are many different concepts in that area. The concept of virtual organization can be formulated on the basis of its characteristic features. Generally, the following features have been indicated: temporary character, focusing on customers, geographical dispersion, intensive use of computer technologies, network organization and use of core competencies of the members. An example of virtual organization could be found in, so called, virtual supply chain, which demonstrates high degree of flexibility and is capable of easy adjustment to dynamic markets. Advanced logistics competencies of companies functioning in that supply chain and their ability to integrate closely with suppliers and customers become the basis of virtual supply chains operations. This paper presents the results of research in the group of Polish companies. As the result of the research more specific picture of the abilities of companies for their operation in virtual (extra-flexible supply chains has been presented. From the point of view of the use of alternative tools for logistics management, logistics providers seem to be the group of firms being the most opened for cooperation. It results directly from the profile of their market operations. Finally, a conclusion might be drawn that a growth of flexibility of virtual supply chains demands more profound specialization of companies constituting links of those chains.
Aligned fibers direct collective cell migration to engineer closing and nonclosing wound gaps.
Sharma, Puja; Ng, Colin; Jana, Aniket; Padhi, Abinash; Szymanski, Paige; Lee, Jerry S H; Behkam, Bahareh; Nain, Amrinder S
2017-09-15
Cell emergence onto damaged or organized fibrous extracellular matrix (ECM) is a crucial precursor to collective cell migration in wound closure and cancer metastasis, respectively. However, there is a fundamental gap in our quantitative understanding of the role of local ECM size and arrangement in cell emergence-based migration and local gap closure. Here, using ECM-mimicking nanofibers bridging cell monolayers, we describe a method to recapitulate and quantitatively describe these in vivo behaviors over multispatial (single cell to cell sheets) and temporal (minutes to weeks) scales. On fiber arrays with large interfiber spacing, cells emerge (invade) either singularly by breaking cell-cell junctions analogous to release of a stretched rubber band (recoil), or in groups of few cells (chains), whereas on closely spaced fibers, multiple chains emerge collectively. Advancing cells on fibers form cell streams, which support suspended cell sheets (SCS) of various sizes and curvatures. SCS converge to form local gaps that close based on both the gap size and shape. We document that cell stream spacing of 375 µm and larger hinders SCS advancement, thus providing abilities to engineer closing and nonclosing gaps. Altogether we highlight the importance of studying cell-fiber interactions and matrix structural remodeling in fundamental and translational cell biology. © 2017 Sharma et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).
Kniss, Andreas; Schuetz, Denise; Kazemi, Sina; Pluska, Lukas; Spindler, Philipp E; Rogov, Vladimir V; Husnjak, Koraljka; Dikic, Ivan; Güntert, Peter; Sommer, Thomas; Prisner, Thomas F; Dötsch, Volker
2018-02-06
Ubiquitination is the most versatile posttranslational modification. The information is encoded by linkage type as well as chain length, which are translated by ubiquitin binding domains into specific signaling events. Chain topology determines the conformational space of a ubiquitin chain and adds an additional regulatory layer to this ubiquitin code. In particular, processes that modify chain length will be affected by chain conformations as they require access to the elongation or cleavage sites. We investigated conformational distributions in the context of chain elongation and disassembly using pulsed electron-electron double resonance spectroscopy in combination with molecular modeling. Analysis of the conformational space of diubiquitin revealed conformational selection or remodeling as mechanisms for chain recognition during elongation or hydrolysis, respectively. Chain elongation to tetraubiquitin increases the sampled conformational space, suggesting that a high intrinsic flexibility of K48-linked chains may contribute to efficient proteasomal degradation. Copyright © 2017 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Bailey, D.
1998-04-01
The Second Processing Chain (CHAIN2) consists of a suite of ten programs which together provide a full local analysis of the bulk plasma physics within the JET Tokamak. In discussing these ten computational models this report is intended to fulfil two broad purposes. Firstly it is meant to be used as a reference source for any user of CHAIN2 data, and secondly it provides a basic User Manual sufficient to instruct anyone in running the CHAIN2 suite of codes. In the main report text each module is described in terms of its underlying physics and any associated assumptions or limitations, whilst deliberate emphasis is put on highlighting the physics and mathematics of the calculations required in deriving each individual datatype in the standard module PPF output. In fact each datatype of the CHAIN2 PPF output listed in Appendix D is cross referenced to the point in the main text where its evaluation is discussed. An effort is made not only to give the equation used to derive a particular data profile but also to explicitly define which external data sources are involved in the computational calculation
DEFF Research Database (Denmark)
Pless, Stephan Alexander; Elstone, Fisal D; Niciforovic, Ana P
2014-01-01
largely enigmatic. To this end, natural and unnatural side chain substitutions were made in the S2 hydrophobic core (HC), the extracellular negative charge cluster (ENC), and the intracellular negative charge cluster (INC) of the four VSDs of the skeletal muscle sodium channel isoform (NaV1......Voltage-gated sodium (NaV) channels mediate electrical excitability in animals. Despite strong sequence conservation among the voltage-sensor domains (VSDs) of closely related voltage-gated potassium (KV) and NaV channels, the functional contributions of individual side chains in Nav VSDs remain.......4). The results show that the highly conserved aromatic side chain constituting the S2 HC makes distinct functional contributions in each of the four NaV domains. No obvious cation-pi interaction exists with nearby S4 charges in any domain, and natural and unnatural mutations at these aromatic sites produce...
Pengukuran Kinerja Supply Chain Dengan Pendekatan Supply Chain Operation References (SCOR
Directory of Open Access Journals (Sweden)
Rizki Wahyuniardi
2017-12-01
Full Text Available PT. Brodo Ganesha Indonesia is a national company engaged in manufacturing with the production of leather shoes. The company has many stakeholders and it is difficult to manage its supply chain, thereby affecting the effectiveness and efficiency of the company's supply chains. The research was conducted to measure the performance of supply chain by using Supply Chain Operation References (SCOR approach. The initial hierarchy model of performance measurement is tailored to the company's condition to measure its supply chain performance, while the normalization of Snorm De Boer serves to equalize the value of the matrix used as the measurement indicator. The level of importance of performance attributes is measured by weighting with subjective questionnaires. Value of performance attribute obtained reliability 19,74, responsiveness 16,91, agility 11,00; and asset management 12.26. The total performance score of 59.90. This value indicates that the performance of the supply chain is in an average position.
Effective food supply chains : generating, modelling and evaluating supply chain scenarios
Vorst, van der J.G.A.J.
2000-01-01
The overall objectives of the research described in this thesis were to obtain insight into the applicability of the concept Supply Chain Management (SCM) in food supply chains (SCs) from a logistical point of view, and to
The influence of CSR, innovation and supply chain partnership on firm competitiveness
Directory of Open Access Journals (Sweden)
Elizabeth Chinomona
2016-11-01
Full Text Available Corporate social responsibility (CSR is crucial for competitive advantage and survival of firms globally. In the pursuit of excellence, many firms have embarked on CSR programs, considering that it is not a financial burden but a strategic roadmap to increase and maintain their brand reputation, to overcome competitive pressures successfully and to efficiently and effectively lower operating cost with profit maximisation through innovation and supply chain partnership. However, in the process of becoming good players of CSR to society, innovative dimension for sustainability as well as an organisation’s supply chain partnership may be essential determinants to enhance good firm business processes and performance activities. In other words, to realise CSR, firms should have a strong environmental measure and well-integrated supply chain practices closely related to their business objectives and structures. The purpose of this paper, therefore, is to examine the influence of CSR on innovation, supply chain partnership and firm competitiveness on firms around Vanderbijlpark, South Africa. Through a quantitative method using smart PLS, this study tested the relationships among the four variables, which are CSR, innovation, supply chain partnership and firm competitiveness. The results showed that there is a positive relationship between the four proposed hypotheses. H1: There is a positive relationship between CSR and innovation; H2: There is a positive relationship between CSR and supply chain partnership; H3: There is a positive relationship between innovation and firm competitiveness; H4: There is a positive relationship between supply chain partnership and firm competitiveness. The proposed study is expected to have practical and theoretical implications to policy makers and managers. In addition, it will provide added insights and new knowledge to the existing body of literature hitherto not studied extensively in South African firms
Characterization of the rat exploratory behavior in the elevated plus-maze with Markov chains.
Tejada, Julián; Bosco, Geraldine G; Morato, Silvio; Roque, Antonio C
2010-11-30
The elevated plus-maze is an animal model of anxiety used to study the effect of different drugs on the behavior of the animal. It consists of a plus-shaped maze with two open and two closed arms elevated 50cm from the floor. The standard measures used to characterize exploratory behavior in the elevated plus-maze are the time spent and the number of entries in the open arms. In this work, we use Markov chains to characterize the exploratory behavior of the rat in the elevated plus-maze under three different conditions: normal and under the effects of anxiogenic and anxiolytic drugs. The spatial structure of the elevated plus-maze is divided into squares, which are associated with states of a Markov chain. By counting the frequencies of transitions between states during 5-min sessions in the elevated plus-maze, we constructed stochastic matrices for the three conditions studied. The stochastic matrices show specific patterns, which correspond to the observed behaviors of the rat under the three different conditions. For the control group, the stochastic matrix shows a clear preference for places in the closed arms. This preference is enhanced for the anxiogenic group. For the anxiolytic group, the stochastic matrix shows a pattern similar to a random walk. Our results suggest that Markov chains can be used together with the standard measures to characterize the rat behavior in the elevated plus-maze. Copyright © 2010 Elsevier B.V. All rights reserved.
Structure of the conversion laws in quantum integrable spin chains with short range interactions
International Nuclear Information System (INIS)
Grabowski, M.P.; Mathieu, P.
1995-01-01
The authors present a detailed analysis of the structure of the conservation laws in quantum integrable chains of the XYZ-type and in the Hubbard model. The essential tool for the former class of models is the boost operator, which provides a recursive way of calculating the integrals of motion. With its help, they establish the general form of the XYZ conserved charges in terms of simple polynomials in spin variables and derive recursion relations for the relative coefficients of these polynomials. Although these relations are difficult to solve in general, a subset of the coefficients can be determined. Moreover, for two submodels of the XYZ chain, namely the XXX and XY cases, all the charges can be calculated in closed form. Using this approach, the authors rederive the known expressions for the XY charges in a novel way. For the XXX case. a simple description of conserved charges is found in terms of a Catalan tree. This construction is generalized for the su(M) invariant integrable chain. They also investigate the circumstances permitting the existence of a recursive (ladder) operator in general quantum integrable systems. They indicate that a quantum ladder operator can be traced back to the presence of a Hamiltonian mastersymmetry of degree one in the classical continuous version of the model. In this way, quantum chains endowed with a recursive structure can be identified from the properties of their classical relatives. The authors also show that in the quantum continuous limits of the XYZ model, the ladder property of the boost operator disappears. For the Hubbard model they demonstrate the nonexistence of a ladder operator. Nevertheless, the general structure of the conserved charges is indicated, and the expression for the terms linear in the model's free parameter for all charges is derived in closed form. 62 refs., 4 figs
International Nuclear Information System (INIS)
Verevkin, Sergey P.; Zaitsau, Dzmitry H.; Emel’yanenko, Vladimir N.; Ralys, Ricardas V.; Yermalayeu, Andrei V.; Schick, Christoph
2013-01-01
Graphical abstract: We have shown that enthalpies of formation, enthalpies of vaporization, and lattice potential energies of alkylsubstituted imidazolium, pyridinium, and pyrrolidinium based ionic liquids with Cl and Br anions are linearly dependant on the alkyl chain length. The thermochemical properties of ILs are generally obey the group additivity rules and the values of the additivity parameters for enthalpies of formation and vaporization are very close to those for molecular compounds. - Highlights: • Alkyl substituted imidazolium, pyridinium, and pyrrolidinium based ionic liquids with anions [Cl] and [Br] were studied using DSC and ab initio methods. • The thermochemical properties of ILs generally obey the group additivity rules. • A linear dependence on the chain length of the alkyl chain of cation was found. - Abstract: DSC was used for determination of reaction enthalpies of synthesis of ionic liquids [C n mim][Cl]. A combination of DSC with quantum chemical calculations presents an indirect way to study thermodynamics of ionic liquids. The indirect procedure for vaporization enthalpy was validated with the direct experimental measurements by using thermogravimetry. First-principles calculations of the enthalpy of formation in the gaseous phase have been performed for the ionic species using the CBS-QB3 and G3 (MP2) theory. Experimental DSC data for homologous series of alkyl substituted imidazolium, pyridinium, and pyrrolidinium based ionic liquids with anions [Cl] and [Br] were collected from the literature. We have shown that enthalpies of formation, enthalpies of vaporization, and lattice potential energies are linearly dependant on the alkyl chain length. The thermochemical properties of ILs generally obey the group additivity rules and the values of the additivity parameters for enthalpies of formation and vaporization seem to be very close to those for molecular compounds
Integrated supply chain risk management
Riaan Bredell; Jackie Walters
2007-01-01
Integrated supply chain risk management (ISCRM) has become indispensable to the theory and practice of supply chain management. The economic and political realities of the modern world require not only a different approach to supply chain management, but also bold steps to secure supply chain performance and sustainable wealth creation. Integrated supply chain risk management provides supply chain organisations with a level of insight into their supply chains yet to be achieved. If correctly ...
Supply-Chain Optimization Template
Quiett, William F.; Sealing, Scott L.
2009-01-01
The Supply-Chain Optimization Template (SCOT) is an instructional guide for identifying, evaluating, and optimizing (including re-engineering) aerospace- oriented supply chains. The SCOT was derived from the Supply Chain Council s Supply-Chain Operations Reference (SCC SCOR) Model, which is more generic and more oriented toward achieving a competitive advantage in business.
International Nuclear Information System (INIS)
Zandvliet, Harold J W; Van Houselt, Arie; Poelsema, Bene
2009-01-01
The structural and electronic properties of self-lacing atomic chains on Pt modified Ge(001) surfaces have been studied using low-temperature scanning tunnelling microscopy and spectroscopy. The self-lacing chains have a cross section of only one atom, are perfectly straight, thousands of atoms long and virtually defect free. The atomic chains are composed of dimers that have their bonds aligned in a direction parallel to the chain direction. At low temperatures the atomic chains undergo a Peierls transition: the periodicity of the chains doubles from a 2 x to a 4 x periodicity and an energy gap opens up. Furthermore, at low temperatures (T<80 K) novel quasi-one-dimensional electronic states are found. These quasi-one-dimensional electronic states originate from an electronic state of the underlying terrace that is confined between the atomic chains.
Wang, Chunguang
Integrable quantum spin chains have close connections to integrable quantum field. theories, modern condensed matter physics, string and Yang-Mills theories. Bethe. ansatz is one of the most important approaches for solving quantum integrable spin. chains. At the heart of the algebraic structure of integrable quantum spin chains is. the quantum Yang-Baxter equation and the boundary Yang-Baxter equation. This. thesis focuses on four topics in Bethe ansatz. The Bethe equations for the isotropic periodic spin-1/2 Heisenberg chain with N. sites have solutions containing ±i/2 that are singular: both the corresponding energy and the algebraic Bethe ansatz vector are divergent. Such solutions must be carefully regularized. We consider a regularization involving a parameter that can be. determined using a generalization of the Bethe equations. These generalized Bethe. equations provide a practical way of determining which singular solutions correspond. to eigenvectors of the model. The Bethe equations for the periodic XXX and XXZ spin chains admit singular. solutions, for which the corresponding eigenvalues and eigenvectors are ill-defined. We use a twist regularization to derive conditions for such singular solutions to bephysical, in which case they correspond to genuine eigenvalues and eigenvectors of. the Hamiltonian. We analyze the ground state of the open spin-1/2 isotropic quantum spin chain. with a non-diagonal boundary term using a recently proposed Bethe ansatz solution. As the coefficient of the non-diagonal boundary term tends to zero, the Bethe roots. split evenly into two sets: those that remain finite, and those that become infinite. We. argue that the former satisfy conventional Bethe equations, while the latter satisfy a. generalization of the Richardson-Gaudin equations. We derive an expression for the. leading correction to the boundary energy in terms of the boundary parameters. We argue that the Hamiltonians for A(2) 2n open quantum spin chains
Supply Chain Systems Architecture and Engineering Design: Green-field Supply Chain Integration
Radanliev, P
2015-01-01
This paper developed a new theory for supply chain architecture, and engineering design that enables integration of the business and supply chain strategies. The architecture starts with individual supply chain participants and derives insights into the complex and abstract concept of green-field integration design. The paper presented a conceptual system for depicting the interactions between business and supply chain strategy engineering. The system examines the decisions made when engineer...
Time Difference Amplifier with Robust Gain Using Closed-Loop Control
Nakura, Toru; Mandai, Shingo; Ikeda, Makoto; Asada, Kunihiro
This paper presents a Time Difference Amplifier (TDA) that amplifies the input time difference into the output time difference. Cross coupled chains of variable delay cells with the same number of stages are applicable for TDA, and the gain is adjusted via the closed-loop control. The TDA was fabricated using 65nm CMOS and the measurement results show that the time difference gain is 4.78 at a nominal power supply while the designed gain is 4.0. The gain is stable enough to be less than 1.4% gain shift under ±10% power supply voltage fluctuation.
'Duality twisted'boundary conditions in n-state Potts Models
International Nuclear Information System (INIS)
Schuetz, G.
1992-11-01
We discuss a new class of toroidal boundary conditions for one-dimensional quantum Hamiltonian with S n symmetry which are related to two-dimensional n-state Potts models in the extreme anisotropic Hamiltonian limit. At their self-dual point (a point were a second-order phase transition occurs for n=2,3,4) the duality transformation is shown to be an additional symmetry giving rise to a new class of 'duality twisted' toroidal boundary conditions. This corresponding Hamiltonians are given in terms of generators of the periodic Temprely-Lieb algebra with an odd number of generators. We discuss as an example the critical Ising model. Here the complete spectrum for the new boundary conditions can be obtained from a projection mechanism in the spin-1/2 XXZ Heisenberg chain. (author)
Supply chain planning classification
Hvolby, Hans-Henrik; Trienekens, Jacques; Bonde, Hans
2001-10-01
Industry experience a need to shift in focus from internal production planning towards planning in the supply network. In this respect customer oriented thinking becomes almost a common good amongst companies in the supply network. An increase in the use of information technology is needed to enable companies to better tune their production planning with customers and suppliers. Information technology opportunities and supply chain planning systems facilitate companies to monitor and control their supplier network. In spite if these developments, most links in today's supply chains make individual plans, because the real demand information is not available throughout the chain. The current systems and processes of the supply chains are not designed to meet the requirements now placed upon them. For long term relationships with suppliers and customers, an integrated decision-making process is needed in order to obtain a satisfactory result for all parties. Especially when customized production and short lead-time is in focus. An effective value chain makes inventory available and visible among the value chain members, minimizes response time and optimizes total inventory value held throughout the chain. In this paper a supply chain planning classification grid is presented based current manufacturing classifications and supply chain planning initiatives.
Leksono, Eko Budi; Suparno, Vanany, Iwan
2017-11-01
The services industry growth has been significant relation with economic growth. A new paradigm is needed for services sector development. The supply chain and performance measurement able to sustain of services industry growth. The supply chain implementation in the services industry called service supply chain (SSC). The globalization and stakeholder pressure makes operation of SSC should more attention to sustainability issue which consists of economic, social and environment simultaneously on SSC. Furthermore, services industry can develop by implementation of the sustainable SSC and its performance measurement. The sustainable SSC implementation can minimize of negative operation effect to environment and social, and maximize of profit. Sustainable service supply chain performance measurements (SSSCPM) are still less explored. The purpose of this paper is to review the literature in the field SSC, SSSC, SSC performance measurement (SSCPM) and SSSCPM for identification of the SSSCPM frameworks and indicators. Beside, the result of review able to look opportunities for develop a new framework for SSSCPM at the operational level, tactical and strategic, multiplayer and close loop, the effectiveness of the integration and development of modeling and simulation for evaluation in the future.
Integrated supply chain risk management
Directory of Open Access Journals (Sweden)
Riaan Bredell
2007-11-01
Full Text Available Integrated supply chain risk management (ISCRM has become indispensable to the theory and practice of supply chain management. The economic and political realities of the modern world require not only a different approach to supply chain management, but also bold steps to secure supply chain performance and sustainable wealth creation. Integrated supply chain risk management provides supply chain organisations with a level of insight into their supply chains yet to be achieved. If correctly applied, this process may optimise management decision-making and assist in the protection and enhancement of shareholder value.
Fresh fish distribution chains: An analysis of three Danish and three Australian chains
DEFF Research Database (Denmark)
Frederiksen, Marco Thorup; Bremner, Allan
2001-01-01
. Traceability is a most important issue in the high value product chains in Australia. No information technology methods, were in evidence. In the Danish chains, nearly all traceability was lost after the collector/auction stage and the only evaluation of quality parameters was by inspection.......Information on traceability was gathered for three domestic Danish fish chains typical of the current trading practices in fresh seafood and for three chains exporting products from Australia to Japan. The same standard questionnaires, coupled with personal interviews, were used in all six chains...
Entanglement Entropy of the N=4 SYM spin chain
International Nuclear Information System (INIS)
Georgiou, George; Zoakos, Dimitrios
2016-01-01
We present a detailed study of the Entanglement Entropy (EE) of excited states in all closed rank one subsectors of N=4 SYM, namely SU(2), SU(1|1) and SL(2). Exploiting the techniques of the Coordinate and the Algebraic Bethe Ansatz we obtain the EE for spin chains with up to seven magnons, at leading order in the coupling expansion but exact in the length of the spin chain and of the part of it that we cut. Focusing on the superconformal primary operator with two magnons in the BMN limit, we derive analytic and exact, in the coupling λ ′ , expressions for the Renyi and the EE. The interpolating functions for the Renyi and the EE monotonically increase as the coupling increases from the weak coupling λ ′ →0 regime to the strong coupling λ ′ →∞ regime. This results to a violation of a certain bound for the EE that is present at weak coupling and confirms the physical intuition that entanglement increases when the coupling increases.
Chain transitivity in hyperspaces
International Nuclear Information System (INIS)
Fernández, Leobardo; Good, Chris; Puljiz, Mate; Ramírez, Ártico
2015-01-01
Given a non-empty compact metric space X and a continuous function f: X → X, we study the dynamics of the induced maps on the hyperspace of non-empty compact subsets of X and on various other invariant subspaces thereof, in particular symmetric products. We show how some important dynamical properties transfer across induced systems. These amongst others include, chain transitivity, chain (weakly) mixing, chain recurrence, exactness by chains. From our main theorem we derive an ε-chain version of Furstenberg’s celebrated 2 implies n Theorem. We also show the implications our results have for dynamics on continua.
Thermodynamics of spin chains of Haldane–Shastry type and one-dimensional vertex models
International Nuclear Information System (INIS)
Enciso, Alberto; Finkel, Federico; González-López, Artemio
2012-01-01
We study the thermodynamic properties of spin chains of Haldane–Shastry type associated with the A N−1 root system in the presence of a uniform external magnetic field. To this end, we exactly compute the partition function of these models for an arbitrary finite number of spins. We then show that these chains are equivalent to a suitable inhomogeneous classical Ising model in a spatially dependent magnetic field, generalizing the results of Basu-Mallick et al. for the zero magnetic field case. Using the standard transfer matrix approach, we are able to compute in closed form the free energy per site in the thermodynamic limit. We perform a detailed analysis of the chains’ thermodynamics in a unified way, with special emphasis on the zero field and zero temperature limits. Finally, we provide a novel interpretation of the thermodynamic quantities of spin chains of Haldane–Shastry type as weighted averages of the analogous quantities over an ensemble of classical Ising models. - Highlights: ► Partition function of spin chains of Haldane–Shastry type in magnetic field. ► Equivalence to classical inhomogeneous Ising models. ► Free energy per site, other thermodynamic quantities in thermodynamic limit. ► Zero field, zero temperature limits. ► Thermodynamic equivalence with ensemble of classical Ising models.
Understanding your supply chain to reduce the risk of supply chain disruption.
Wildgoose, Nick; Brennan, Patrick; Thompson, Simon
2012-01-01
Supply chains are at the heart of the way in which organisations operate and compete today; they also play a critical role in overall organisation performance. In the context of increasingly complex and global supply chains, the actions taken to drive down costs are likely to drive risk into the supply chain. The frequency of supply chain disruptions is high and this paper offers practical advice to help reduce the frequency and cost associated with these. There is advice to help with the understanding of how to identify critical suppliers. The reader is guided through comprehensive risk assessment and mitigation approaches and a selection of practical risk solutions and tools that you can use is described. There is a section on the 'dos and don'ts' relating to supplier due diligence. For those organisations facing the challenge of drawing up a business case relating to investment in improving supply chain resiliency, there is also a section outlining some of the business benefits of improving supply chain resiliency.
Vieraşu, T.; Bălăşescu, M.
2011-01-01
In this article I will go through three main logistics components, which are represented by: transportation, inventory and facilities, and the three secondary logistical components: information, production location, price and how they determine performance of any supply chain. I will discuss then how these components are used in the design, planning and operation of a supply chain. I will also talk about some obstacles a supply chain manager may encounter.
Plasmon assisted control of photo-induced excitation energy transfer in a molecular chain
Wang, Luxia; May, Volkhard
2017-08-01
The strong and ultrafast laser pulse excitation of a molecular chain in close vicinity to a spherical metal nano-particle (MNP) is studied theoretically. Due to local-field enhancement around the MNP, pronounced excited-state formation has to be expected for the part of the chain which is in proximity to the MNP. Here, the description of this phenomenon will be based on a uniform quantum theory of the MNP-molecule system. It accounts for local-field effects due to direct consideration of the strong excitation energy transfer coupling between the MNP and the various molecules. The molecule-MNP distances are chosen in such a way as to achieve a correct description of the MNP via dipole-plasmon excitations. Short plasmon life-times are incorporated in the framework of a density matrix approach. By extending earlier work the present description allows for multi-exciton formation and multiple dipole-plasmon excitation. The region of less intense and not-too-short optical excitation is identified as being best suited for excitation energy localization in the chain.
Pricing Decisions of a Dual-Channel Supply Chain considering Supply Disruption Risk
Directory of Open Access Journals (Sweden)
Yancong Zhou
2018-01-01
Full Text Available Supply disruption may cause strong complaints of customers, which is a cost loss for the firms in the supply chain. Obviously, if realizing that there is the disruption risk, the members in a supply chain will adjust their decisions. For analyzing the influence, we consider a popular supply chain mode with dual channels, where one manufacturer has its direct sales channel and one traditional retailer channel. The manufacturer may suffer a supply disruption so that all ordered products by the retailer or the direct retail channel will be lost, and the members in supply chain will bear the corresponding disruption penalty from the customers. By considering four structures with different market power relations, the closed-form optimal price decisions of the four models are given. We found that the disruption factor improves the sales prices for any member structure as compared to the supply chain without the disruption. And the direct retail prices in the different modes are the same as each other, but the price of the traditional channel is influenced by the market share. And the sorts of the sales prices under different structures are given. We also conduct some extensive numerical analysis and compare the results under different structures. We observe that the expected optimal profits of considering the external penalty are smaller than those of no external penalty, and we give a sort of the optimal expected profits. And we also provide the effects of some parameters on the optimal decisions and the optimal expected profits.
How to Bring Sustainability Issues in Global Supply Chains into the Classroom?
DEFF Research Database (Denmark)
Schramm, Hans-Joachim; Anderluh, Alexandra
2016-01-01
: Based on the discussions with our students and post-course reflective reports it turned out, that for many of them their perception of sustainability issues and of their own behaviour has changed during this single week because of the topics dealt with in our course. Practical implications: A well......Purpose: Sustainability is one of the major key terms in our modern globalized world affected by such different but nevertheless closely interrelated issues like prosperity of worldwide trade, globally-spanning supply chains, the growing social gap and the threatening effects of climate change...... thought-out didactic approach and extraordinary commitment and dedication by the instructors is inevitable to ensure the success of such a course. Original/value: This paper explains in a compact way, how sustainability issues in global supply chain management can be tackled successfully even in such time...
DEFF Research Database (Denmark)
Neergaard, Jesper; Schieber, Jay D.
1999-01-01
A self-consistent reptation model that includes chain stretching, chain-length fluctuations, segment connectivity and constraint release is used to predict transient and steady flows. Quantitative comparisons are made with entangledsolution data. The model is able to capture quantitatively all...
Measuring performance at the supply chain level: the role of the chain director
Directory of Open Access Journals (Sweden)
Job A.C. De Haan
2016-05-01
The findings show when an attempt to implement a PMS at the supply chain level might be appropriate and effective (if a chain exists and has a director, and how the system’s content should be focused on what is needed to improve chain performance (with end customers’ demands as a starting point. The paper highlights the benefits obtained by the other partners if they comply with the best informed supply chain member in the development of the chain’s PMS, as well as how a PMS cannot be developed when none of the partners can be labelled as chain director.
Supply Chain Management Practices in Toy Supply Chains
DEFF Research Database (Denmark)
Arlbjørn, Jan Stentoft; Johansen, J.; Wong, C. Y.
2005-01-01
Purpose - Innovative products usually experience highly unpredictable and variable demand. This is especially valid for the volatile and seasonal toy industry, which produces high obsolete inventory, lost sales and markdown. In such a volatile industry, what supply chain management (SCM) practices...... (traditional mass-production or push-models). These low-responsive practices in the toy supply chain are not caused only by slow knowledge diffusion. SCM know-how is not yet capable of managing such levels of volatility and seasonality. Therefore, explanations of these theoretical gaps and what new theories...... are required for such extreme volatility and seasonality are proposed. Originality/value - It reveals actual SCM practices in a volatile and seasonal supply chain, such that theoretical and practical gaps are identified. Also, it proposes a model to match manufacturing SCM-practices with retailer SCM-practices....
Cultivating a disease management partnership: a value-chain model.
Murray, Carolyn F; Monroe, Wendy; Stalder, Sharon A
2003-01-01
Disease management (DM) is one of the health care industry's more innovative value-chain models, whereby multiple relationships are created to bring complex and time-sensitive services to market. The very nature of comprehensive, seamless DM provided through an outsourced arrangement necessitates a level of cooperation, trust, and synergy that may be lacking from more traditional vendor-customer relationships. This discussion highlights the experience of one health plan and its vendor partner and their approach to the development and delivery of an outsourced heart failure (HF) DM program. The program design and rollout are discussed within principles adapted from the theoretical framework of a value-chain model. Within the value-chain model, added value is created by the convergence and synergistic integration of the partners' discrete strengths. Although each partner brings unique attributes to the relationship, those attributes are significantly enhanced by the value-chain model, thus allowing each party to bring the added value of the relationship to their respective customers. This partnership increases innovation, leverages critical capabilities, and improves market responsiveness. Implementing a comprehensive, outsourced DM program is no small task. DM programs incorporate a broad array of services affecting nearly every department in a health plan's organization. When true seamless integration between multiple organizations with multiple stakeholders is the objective, implementation and ongoing operations can become even more complex. To effectively address the complexities presented by an HF DM program, the parties in this case moved beyond a typical purchaser-vendor relationship to one that is more closely akin to a strategic partnership. This discussion highlights the development of this partnership from the perspective of both organizations, as revealed through contracting and implementation activities. It is intended to provide insight into the program
Directory of Open Access Journals (Sweden)
Vieraşu, T.
2011-01-01
Full Text Available In this article I will go through three main logistics components, which are represented by: transportation, inventory and facilities, and the three secondary logistical components: information, production location, price and how they determine performance of any supply chain. I will discuss then how these components are used in the design, planning and operation of a supply chain. I will also talk about some obstacles a supply chain manager may encounter.
janssen, Anja; Segers, Johan
2013-01-01
The extremes of a univariate Markov chain with regularly varying stationary marginal distribution and asymptotically linear behavior are known to exhibit a multiplicative random walk structure called the tail chain. In this paper we extend this fact to Markov chains with multivariate regularly varying marginal distributions in Rd. We analyze both the forward and the backward tail process and show that they mutually determine each other through a kind of adjoint relation. In ...
DEFF Research Database (Denmark)
Sørensen, Olav Jull
The conference paper aims to develop the global value chain concept by including corporate internal value adding activities and competition to the basic framework in order to turn the global value chain into a strategic management tool......The conference paper aims to develop the global value chain concept by including corporate internal value adding activities and competition to the basic framework in order to turn the global value chain into a strategic management tool...
A new approach for supply chain risk management: Mapping SCOR into Bayesian network
Directory of Open Access Journals (Sweden)
Mahdi Abolghasemi
2015-01-01
Full Text Available Purpose: Increase of costs and complexities in organizations beside the increase of uncertainty and risks have led the managers to use the risk management in order to decrease risk taking and deviation from goals. SCRM has a close relationship with supply chain performance. During the years different methods have been used by researchers in order to manage supply chain risk but most of them are either qualitative or quantitative. Supply chain operation reference (SCOR is a standard model for SCP evaluation which have uncertainty in its metrics. In This paper by combining qualitative and quantitative metrics of SCOR, supply chain performance will be measured by Bayesian Networks. Design/methodology/approach: First qualitative assessment will be done by recognizing uncertain metrics of SCOR model and then by quantifying them, supply chain performance will be measured by Bayesian Networks (BNs and supply chain operations reference (SCOR in which making decision on uncertain variables will be done by predictive and diagnostic capabilities. Findings: After applying the proposed method in one of the biggest automotive companies in Iran, we identified key factors of supply chain performance based on SCOR model through predictive and diagnostic capability of Bayesian Networks. After sensitivity analysis, we find out that ‘Total cost’ and its criteria that include costs of labors, warranty, transportation and inventory have the widest range and most effect on supply chain performance. So, managers should take their importance into account for decision making. We can make decisions simply by running model in different situations. Research limitations/implications: A more precise model consisted of numerous factors but it is difficult and sometimes impossible to solve big models, if we insert all of them in a Bayesian model. We have adopted real world characteristics with our software and method abilities. On the other hand, fewer data exist for some
Arkaravichien, Wiwat; Wongpratat, Apichaya; Lertsinudom, Sunee
2016-08-01
Background Quality indicators determine the quality of actual practice in reference to standard criteria. The Community Pharmacy Association (Thailand), with technical support from the International Pharmaceutical Federation, developed a tool for quality assessment and quality improvement at community pharmacies. This tool has passed validity and reliability tests, but has not yet had feasibility testing. Objective (1) To test whether this quality tool could be used in routine settings. (2) To compare quality scores between accredited independent and accredited chain pharmacies. Setting Accredited independent pharmacies and accredited chain pharmacies in the north eastern region of Thailand. Methods A cross sectional study was conducted in 34 accredited independent pharmacies and accredited chain pharmacies. Quality scores were assessed by observation and by interviewing the responsible pharmacists. Data were collected and analyzed by independent t-test and Mann-Whitney U test as appropriate. Results were plotted by histogram and spider chart. Main outcome measure Domain's assessable scores, possible maximum scores, mean and median of measured scores. Results Domain's assessable scores were close to domain's possible maximum scores. This meant that most indicators could be assessed in most pharmacies. The spider chart revealed that measured scores in the personnel, drug inventory and stocking, and patient satisfaction and health promotion domains of chain pharmacies were significantly higher than those of independent pharmacies (p pharmacies and chain pharmacies in the premise and facility or dispensing and patient care domains. Conclusion Quality indicators developed by the Community Pharmacy Association (Thailand) could be used to assess quality of practice in pharmacies in routine settings. It is revealed that the quality scores of chain pharmacies were higher than those of independent pharmacies.
Cancilla, M R; Powell, I B; Hillier, A J; Davidson, B E
1992-01-01
Arbitrarily primed polymerase chain reaction, with incorporation of either radioactive or fluorescent labels, was used as a rapid and sensitive method for obtaining genomic fingerprints of strains of Lactococcus lactis. Closely related strains produced almost identical fingerprints. Fingerprints of other strains showed only some similarities.
On H-closed and U-closed functions | Cammaroto | Quaestiones ...
African Journals Online (AJOL)
In this article, we extend the work on H-closed functions started by Cammaroto, Fedorchuk and Porter in 1998. Also, U-closed functions are introduced and characterized in terms of filters and adherence. The hereditary and productivity properties are examined and developed for both H-closed and U-closed functions.
Nelson, Peter N.; Ellis, Henry A.; Taylor, Richard A.
2014-01-01
Lattice structures and thermal behaviours for some long chain potassium carboxylates (nc = 8-18, inclusive) are investigated using Fourier Transform Infrared spectroscopy, X-ray Powder Diffraction, Solid State spin decoupled 13C NMR spectroscopy, Differential Scanning Calorimetry and Thermogravimetry. The measurements show that the carboxyl groups are coordinated to potassium atoms via asymmetric chelating bidentate bonding, with extensive carboxyl intermolecular interactions to yield tetrahedral metal centers, irrespective of chain length. Furthermore, the hydrocarbon chains are crystallized in the fully extended all-trans configuration and are arranged as non-overlapping lamellar bilayer structures with closely packed methyl groups from opposite layers. Additionally, odd-even alternation, observed in density and methyl group chemical shift, is ascribed to the relative vertical distances between layers in the bilayer, that are not in the same plane. Therefore, for even chain homologues, where this distances is less than for odd chain adducts, more intimate packing is indicated. The phase sequences for all compounds show several reversible crystal-crystal transition associated with kinetically controlled gauche-trans isomerism of the polymethylene chains which undergo incomplete fusion when heated to the melt. The compounds degrade above 785 K to yield carbon dioxide, water, potassium oxide and an alkene.
a Multi Objective Model for Optimization of a Green Supply Chain Network
Paksoy, Turan; Özceylan, Eren; Weber, Gerhard-Wilhelm
2010-06-01
This study develops a model of a closed-loop supply chain (CLSC) network which starts with the suppliers and recycles with the decomposition centers. As a traditional network design, we consider minimizing the all transportation costs and the raw material purchasing costs. To pay attention for the green impacts, different transportation choices are presented between echelons according to their CO2 emissions. The plants can purchase different raw materials in respect of their recyclable ratios. The focuses of this paper are conducting the minimizing total CO2 emissions. Also we try to encourage the customers to use recyclable materials as an environmental performance viewpoint besides minimizing total costs. A multi objective linear programming model is developed via presenting a numerical example. We close the paper with recommendations for future researches.
Bøge Sørensen, Lars
2004-01-01
Keywords Supply Chain Management, Supply Chain Design, Literature study Abstract Argues stability is a design objective for supply chain design alongside cost, lead time and responsiveness. Performs an extensive literature study on supply chain design, identifies methods, theories and objectives in the existing literature. Describes the concept external specificity and how it’s used to design supply chains. Using the concept upstream, archetypes of risk minimal and maximal desi...
Analysis of Supply Chain Risk Management Strategies: Case Study of Supply Chain Disruptions
Marcelo Dias Carvalho; Leticia Ishikawa
2016-01-01
Supply Chain Risk Management refers to a set of strategies used by companies to avoid supply chain disruption caused by damage at production facilities, natural disasters, capacity issues, inventory problems, incorrect forecasts, and delays. Many companies use the techniques of the Toyota Production System, which in a way goes against a better management of supply chain risks. This paper studies key events in some multinationals to analyze the trade-off between the best supply chain risk mana...
Editorial: Supply Chain Management
Directory of Open Access Journals (Sweden)
Dimitrios Aidonis
2017-05-01
Full Text Available This special issue has followed up the 3rd Olympus International Conference on Supply Chains held on Athens Metropolitan Expo, November 7 & 8 2015, Greece. The Conference was organized by the Department of Logistics Technological Educational Institute of Central Macedonia, in collaboration with the: a Laboratory of Quantitative Analysis, Logistics and Supply Chain Management of the Department of Mechanical Engineering, Aristotle University of Thessaloniki (AUTH, b Greek Association of Supply Chain Management (EEL of Northern Greece and the c Supply Chain & Logistics Journal. During the 2-Days Conference more than 60 research papers were presented covering the following thematic areas: (i Transportation, (ii Best Practices in Logistics, (iii Information and Communication Technologies in Supply Chain Management, (iv Food Logistics, (v New Trends in Business Logistics, and (vi Green Supply Chain Management. Three keynote invited speakers addressed interesting issues for the Operational Research, the Opportunities and Prospects of Greek Ports chaired Round Tables with other Greek and Foreign Scientists and Specialists.
Wever, Mark; Wognum, Nel; Trienekens, Jacques; Omta, Onno
2010-02-01
Although inter-firm coordination of quality management is increasingly important for meeting end-customer demand in agri-food chains, few researchers focus on the relation between inter-firm quality management systems (QMS) and inter-firm governance structures (GS). However, failure to align QMSs and GSs may lead to inefficiencies in quality management because of high transaction-costs. In addition, misalignment is likely to reduce the quality of end-customer products. This paper addresses this gap in research by empirically examining the relation between QMSs and GSs in pork meat supply chains. Transaction-Cost-Economic theory is used to develop propositions about the relation between three aspects of QMSs--ownership, vertical scope and scale of adoption--and the use of different types of GSs in pork meat supply chains. To validate the propositions, seven cases are examined from four different countries. The results show that the different aspects of QMSs largely relate to specific GSs used in chains in the manner predicted by the propositions. This supports the view that alignment between QMSs and GSs is important for the efficient coordination of quality management in (pork meat) supply chains.
DEFF Research Database (Denmark)
Bøge Sørensen, Lars
2004-01-01
Keywords Supply Chain Management, Supply Chain Design, Literature studyAbstract Argues stability is a design objective for supply chain design alongside cost, leadtime and responsiveness. Performs an extensive literature study on supply chain design,identifies methods, theories and objectives...... in the existing literature. Describes the conceptexternal specificity and how it's used to design supply chains. Using the concept upstream,archetypes of risk minimal and maximal design are identified. Downstream the conceptdescribes two viable scenarios, one minimizing the impact, the other minimizing...... theprobability of (intended) departure of a supply chain partner. Finally, principles for supplychain design are described and managerial outlined....
Requirements of supply chain management in differentiating European pork chains
Trienekens, J.H.; Wognum, P.M.
2013-01-01
This paper summarizes results obtained by research into pork chain management in the EU Integrated Project Q-Porkchains. Changing demands for intrinsic and extrinsic quality attributes of pork products impact the way supply chain management should be organized from the farmer down to the consumer.
Fitting timeseries by continuous-time Markov chains: A quadratic programming approach
International Nuclear Information System (INIS)
Crommelin, D.T.; Vanden-Eijnden, E.
2006-01-01
Construction of stochastic models that describe the effective dynamics of observables of interest is an useful instrument in various fields of application, such as physics, climate science, and finance. We present a new technique for the construction of such models. From the timeseries of an observable, we construct a discrete-in-time Markov chain and calculate the eigenspectrum of its transition probability (or stochastic) matrix. As a next step we aim to find the generator of a continuous-time Markov chain whose eigenspectrum resembles the observed eigenspectrum as closely as possible, using an appropriate norm. The generator is found by solving a minimization problem: the norm is chosen such that the object function is quadratic and convex, so that the minimization problem can be solved using quadratic programming techniques. The technique is illustrated on various toy problems as well as on datasets stemming from simulations of molecular dynamics and of atmospheric flows
Lee, Hau L
2004-10-01
Building a strong supply chain is essential for business success. But when it comes to improving their supply chains, few companies take the right approach. Many businesses work to make their chains faster or more cost-effective, assuming that those steps are the keys to competitive advantage. To the contrary: Supply chains that focus on speed and costs tend to deteriorate over time. The author has spent 15 years studying more than 60 companies to gain insight into this and other supply chain dilemmas. His conclusion: Only companies that build supply chains that are agile, adaptable, and aligned get ahead of their rivals. All three components are essential; without any one of them, supply chains break down. Great companies create supply chains that respond to abrupt changes in markets. Agility is critical because in most industries, both demand and supply fluctuate rapidly and widely. Supply chains typically cope by playing speed against costs, but agile ones respond both quickly and cost-efficiently. Great companies also adapt their supply networks when markets or strategies change. The best supply chains allow managers to identify structural shifts early by recording the latest data, filtering out noise, and tracking key patterns. Finally, great companies align the interests of the partners in their supply chains with their own. That's important because every firm is concerned solely with its own interests. If its goals are out of alignment with those of other partners in the supply chain, performance will suffer. When companies hear about the triple-A supply chain, they assume that building one will require increased technology and investment. But most firms already have the infrastructure in place to create one. A fresh attitude alone can go a long way toward making it happen.
The composite supply chain efficiency model: A case study of the Sishen-Saldanha supply chain
Directory of Open Access Journals (Sweden)
Leila L. Goedhals-Gerber
2016-01-01
Full Text Available As South Africa strives to be a major force in global markets, it is essential that South African supply chains achieve and maintain a competitive advantage. One approach to achieving this is to ensure that South African supply chains maximise their levels of efficiency. Consequently, the efficiency levels of South Africa’s supply chains must be evaluated. The objective of this article is to propose a model that can assist South African industries in becoming internationally competitive by providing them with a tool for evaluating their levels of efficiency both as individual firms and as a component in an overall supply chain. The Composite Supply Chain Efficiency Model (CSCEM was developed to measure supply chain efficiency across supply chains using variables identified as problem areas experienced by South African supply chains. The CSCEM is tested in this article using the Sishen-Saldanda iron ore supply chain as a case study. The results indicate that all three links or nodes along the Sishen-Saldanha iron ore supply chain performed well. The average efficiency of the rail leg was 97.34%, while the average efficiency of the mine and the port were 97% and 95.44%, respectively. The results also show that the CSCEM can be used by South African firms to measure their levels of supply chain efficiency. This article concludes with the benefits of the CSCEM.
International Nuclear Information System (INIS)
John C. Fisher
2000-01-01
Although helium atoms do not form molecules, a sufficiently large number will bind into a stable liquid droplet. A comparable situation is expected for neutrons, with a sufficiently large number binding into a stable droplet of neutron matter. Such polyneutron droplets can be viewed as isotopes of an element with nuclear charge Z=0, tentatively denoted neutrium, symbol Nt. Because of the relatively weak binding of neutrons compared with that of a mix of neutrons and protons, the minimum number of neutrons required for stability of a droplet is fairly large. Early estimates of ∼60 may be reduced to a dozen or so by the BCS pairing interaction. The Nt entries with N≥12 are new to the table of isotopes. Because all of them are beta-unstable, none is expected to persist as a free particle. Yet, some may occasionally be produced by means to be described below, and it is of interest to examine their decay chains and their interactions with charged nuclei to ascertain how their presence might be revealed. Although these reactions are interesting, they cannot be taken seriously without identifying a source for the initial Nt isotope that begins the chain. Here, we consider possible interactions between 16 O and A Nt. Although there is no strong interaction between them, we can expect a very weak residual attraction that can form a loosely bound 16 O A Nt nuclear molecule. This is not a compound nucleus in the usual sense because, considered as fluids, the 16 O and A Nt droplets are immiscible. For a droplet with fewer than about 60 neutrons, beta decay of A Nt is prevented by the buildup of Coulomb energy associated with transforming A Nt into A H in close proximity to 16 O. Thus, it is possible that 16 O A Nt molecules can persist indefinitely and that a few of them may be present in ordinary water as supermassive oxygen nuclei. Because the binding of these molecules is weak, the A Nt component can tunnel to an adjacent nucleus, and if the adjacent nucleus is 18 O, a
Dynamical properties of the S =1/2 random Heisenberg chain
Shu, Yu-Rong; Dupont, Maxime; Yao, Dao-Xin; Capponi, Sylvain; Sandvik, Anders W.
2018-03-01
We study dynamical properties at finite temperature (T ) of Heisenberg spin chains with random antiferromagnetic exchange couplings, which realize the random singlet phase in the low-energy limit, using three complementary numerical methods: exact diagonalization, matrix-product-state algorithms, and stochastic analytic continuation of quantum Monte Carlo results in imaginary time. Specifically, we investigate the dynamic spin structure factor S (q ,ω ) and its ω →0 limit, which are closely related to inelastic neutron scattering and nuclear magnetic resonance (NMR) experiments (through the spin-lattice relaxation rate 1 /T1 ). Our study reveals a continuous narrow band of low-energy excitations in S (q ,ω ) , extending throughout the q space, instead of being restricted to q ≈0 and q ≈π as found in the uniform system. Close to q =π , the scaling properties of these excitations are well captured by the random-singlet theory, but disagreements also exist with some aspects of the predicted q dependence further away from q =π . Furthermore we also find spin diffusion effects close to q =0 that are not contained within the random-singlet theory but give non-negligible contributions to the mean 1 /T1 . To compare with NMR experiments, we consider the distribution of the local relaxation rates 1 /T1 . We show that the local 1 /T1 values are broadly distributed, approximately according to a stretched exponential. The mean 1 /T1 first decreases with T , but below a crossover temperature it starts to increase and likely diverges in the limit of a small nuclear resonance frequency ω0. Although a similar divergent behavior has been predicted and experimentally observed for the static uniform susceptibility, this divergent behavior of the mean 1 /T1 has never been experimentally observed. Indeed, we show that the divergence of the mean 1 /T1 is due to rare events in the disordered chains and is concealed in experiments, where the typical 1 /T1 value is accessed.
Sydor, Tobias; von Bargen, Kristine; Hsu, Fong-Fu; Huth, Gitta; Holst, Otto; Wohlmann, Jens; Becken, Ulrike; Dykstra, Tobias; Söhl, Kristina; Lindner, Buko; Prescott, John F; Schaible, Ulrich E; Utermöhlen, Olaf; Haas, Albert
2013-03-01
Rhodococcus equi is a close relative of Mycobacterium spp. and a facultative intracellular pathogen which arrests phagosome maturation in macrophages before the late endocytic stage. We have screened a transposon mutant library of R. equi for mutants with decreased capability to prevent phagolysosome formation. This screen yielded a mutant in the gene for β-ketoacyl-(acyl carrier protein)-synthase A (KasA), a key enzyme of the long-chain mycolic acid synthesizing FAS-II system. The longest kasA mutant mycolic acid chains were 10 carbon units shorter than those of wild-type bacteria. Coating of non-pathogenic E. coli with purified wild-type trehalose dimycolate reduced phagolysosome formation substantially which was not the case with shorter kasA mutant-derived trehalose dimycolate. The mutant was moderately attenuated in macrophages and in a mouse infection model, but was fully cytotoxic.Whereas loss of KasA is lethal in mycobacteria, R. equi kasA mutant multiplication in broth was normal proving that long-chain mycolic acid compounds are not necessarily required for cellular integrity and viability of the bacteria that typically produce them. This study demonstrates a central role of mycolic acid chain length in diversion of trafficking by R. equi. © 2012 Blackwell Publishing Ltd.
Performance analysis of Supply Chain Management with Supply Chain Operation reference model
Hasibuan, Abdurrozzaq; Arfah, Mahrani; Parinduri, Luthfi; Hernawati, Tri; Suliawati; Harahap, Bonar; Rahmah Sibuea, Siti; Krianto Sulaiman, Oris; purwadi, Adi
2018-04-01
This research was conducted at PT. Shamrock Manufacturing Corpora, the company is required to think creatively to implement competition strategy by producing goods/services that are more qualified, cheaper. Therefore, it is necessary to measure the performance of Supply Chain Management in order to improve the competitiveness. Therefore, the company is required to optimize its production output to meet the export quality standard. This research begins with the creation of initial dimensions based on Supply Chain Management process, ie Plan, Source, Make, Delivery, and Return with hierarchy based on Supply Chain Reference Operation that is Reliability, Responsiveness, Agility, Cost, and Asset. Key Performance Indicator identification becomes a benchmark in performance measurement whereas Snorm De Boer normalization serves to equalize Key Performance Indicator value. Analiytical Hierarchy Process is done to assist in determining priority criteria. Measurement of Supply Chain Management performance at PT. Shamrock Manufacturing Corpora produces SC. Responsiveness (0.649) has higher weight (priority) than other alternatives. The result of performance analysis using Supply Chain Reference Operation model of Supply Chain Management performance at PT. Shamrock Manufacturing Corpora looks good because its monitoring system between 50-100 is good.
Radiation induced solid-state polymerization of long-chain acrylates containing fluorocarbon chain
International Nuclear Information System (INIS)
Shibasaki, Y.; Zhu, Zhi-Qin
1995-01-01
γ-Ray irradiation post-polymerizations of long-chain acrylates containing fluorocarbon chain, H(CF 2 ) 10 CH 2 OCOCH=CH 2 and H(CF 2 ) 8 CH 2 OCOCH=CH 2 , were investigated and also the structures and thermal properties of comb-like polymers obtained were studied. It was found that these monomers exhibited very high polymerizability at wide temperature ranges around the melting points. Because the fluorocarbon chains are less flexible and thicker than the hydrocarbon chains, it can be expected that the aggregation force among the monomer molecules is strong and the conformational freedom of functional group for polymerization is large. According to the DSC and the X-ray diffraction measurements of the comb-like polymers obtained, the fluorocarbon chains are aggregated in a mode of hexagonal packing in the lamellar crystals. This situation can be considered as an optimum condition for the γ-ray irradiation post-polymerization. (author)
USING A NEW SUPPLY CHAIN PLANNING METHODOLOGY TO IMPROVE SUPPLY CHAIN EFFICIENCY
Directory of Open Access Journals (Sweden)
A.L.V. Raubenheimer
2012-01-01
Full Text Available
ENGLISH ABSTRACT: Effective supply chain planning and management has emerged as one of the most challenging opportunities for companies in the global economy during the last decade or two. This article reviews the evolution of Supply Chain Management and the traditional Supply Chain Solutions. It then introduces a new Supply Chain Planning methodology in which simulation modelling plays an important value-adding role to help organisations understand the dynamics of their Supply Chains.
AFRIKAANSE OPSOMMING:Effektiewe voorsieningskettingbeplanning en –bestuur het gedurende die laaste twee dekades ontwikkel tot een van die mees uitdagende geleenthede vir ondernemings in die wêreldekonomie. Hierdie artikel hersien kortliks die ontwikkeling van voorsieningskettingbestuur en die tradisionele oplossings. ‘n Nuwe voorsieningskettingbeplanningsmetodologie word dan voorgestel en bespreek waarin simulasiemodellering ‘n belangrike rol speel om ondernemings te help om die dinamika van hul voorsieningskettings te begryp.
The role of enterprise systems in supply chain networks: a taxonomy of supply chain strategies
DEFF Research Database (Denmark)
Møller, Charles
2006-01-01
in the supply chain and to choose the right supply chain strategy. The work is based on a comprehensive study of the Supply Chain Management (SCM) and Enterprise Resource Planning (ERP) literature and the study suggests that there is an emerging new research potential for Enterprise Systems (ES) in the supply......This paper proposes a taxonomy for supply chain integration strategies. The taxonomy is based on the contingencies of supply chain network coupling and the Extended Enterprise Systems (EES) architecture in the supply chain. The purpose of this model is to map the portfolio of relations...
International Nuclear Information System (INIS)
Kwapiński, Tomasz
2017-01-01
The electron transport properties of a linear atomic chain are studied theoretically within the tight-binding Hamiltonian and the Green’s function method. Variations of the local density of states (DOS) along the chain are investigated. They are crucial in scanning tunnelling experiments and give important insight into the electron transport mechanism and charge distribution inside chains. It is found that depending on the chain parity the local DOS at the Fermi level can form cone-like structures (DOS cones) along the chain. The general condition for the local DOS oscillations is obtained and the linear behaviour of the local density function is confirmed analytically. DOS cones are characterized by a linear decay towards the chain which is in contrast to the propagation properties of charge density waves, end states and Friedel oscillations in one-dimensional systems. We find that DOS cones can appear due to non-resonant electron transport, the spin–orbit scattering or for chains fabricated on a substrate with localized electrons. It is also shown that for imperfect chains (e.g. with a reduced coupling strength between two neighboring sites) a diamond-like structure of the local DOS along the chain appears. (paper)
Kwapiński, Tomasz
2017-03-01
The electron transport properties of a linear atomic chain are studied theoretically within the tight-binding Hamiltonian and the Green’s function method. Variations of the local density of states (DOS) along the chain are investigated. They are crucial in scanning tunnelling experiments and give important insight into the electron transport mechanism and charge distribution inside chains. It is found that depending on the chain parity the local DOS at the Fermi level can form cone-like structures (DOS cones) along the chain. The general condition for the local DOS oscillations is obtained and the linear behaviour of the local density function is confirmed analytically. DOS cones are characterized by a linear decay towards the chain which is in contrast to the propagation properties of charge density waves, end states and Friedel oscillations in one-dimensional systems. We find that DOS cones can appear due to non-resonant electron transport, the spin-orbit scattering or for chains fabricated on a substrate with localized electrons. It is also shown that for imperfect chains (e.g. with a reduced coupling strength between two neighboring sites) a diamond-like structure of the local DOS along the chain appears.
Chain Dynamics in Magnetorheological Suspensions
Gast, A. P.; Furst, E. M.
1999-01-01
Magnetorheological (MR) suspensions are composed of colloidal particles which acquire dipole moments when subjected to an external magnetic field. At sufficient field strengths and concentrations, the dipolar particles rapidly aggregate to form long chains. Subsequent lateral cross-linking of the dipolar chains is responsible for a rapid liquid-to-solid-like rheological transition. The unique, magnetically-activated rheological properties of MR suspensions make them ideal for interfacing mechanical systems to electronic controls. Additionally, the ability to experimentally probe colloidal suspensions interacting through tunable anisotropic potentials is of fundamental interest. Our current experimental work has focused on understanding the fluctuations of dipolar chains. It has been proposed by Halsey and Toor (HT) that the strong Landau-Peierls thermal fluctuations of dipolar chains could be responsible for long-range attractions between chains. Such interactions will govern the long-time relaxation of MR suspensions. We have synthesized monodisperse neutrally buoyant MR suspensions by density matching stabilized ferrofluid emulsion droplets with D2O. This allows us to probe the dynamics of the dipolar chains using light scattering without gravitational, interfacial, and polydispersity effects to resolve the short-wavelength dynamics of the dipolar chains. We used diffusing wave spectroscopy to measure these dynamics. The particle displacements at short times that show an independence to the field strength, but at long times exhibit a constrained, sub-diffusive motion that slows as the dipole strength is increased. The experiments are in good qualitative agreement with Brownian dynamics simulations of dipolar chains. Although there have been several important and detailed studies of the structure and interactions in MR suspensions, there has not been conclusive evidence that supports or contradicts the HT model prediction that long-range interactions exist between
Büttner, Kathrin; Krieter, Joachim; Traulsen, Arne; Traulsen, Imke
2013-01-01
Centrality parameters in animal trade networks typically have right-skewed distributions, implying that these networks are highly resistant against the random removal of holdings, but vulnerable to the targeted removal of the most central holdings. In the present study, we analysed the structural changes of an animal trade network topology based on the targeted removal of holdings using specific centrality parameters in comparison to the random removal of holdings. Three different time periods were analysed: the three-year network, the yearly and the monthly networks. The aim of this study was to identify appropriate measures for the targeted removal, which lead to a rapid fragmentation of the network. Furthermore, the optimal combination of the removal of three holdings regardless of their centrality was identified. The results showed that centrality parameters based on ingoing trade contacts, e.g. in-degree, ingoing infection chain and ingoing closeness, were not suitable for a rapid fragmentation in all three time periods. More efficient was the removal based on parameters considering the outgoing trade contacts. In all networks, a maximum percentage of 7.0% (on average 5.2%) of the holdings had to be removed to reduce the size of the largest component by more than 75%. The smallest difference from the optimal combination for all three time periods was obtained by the removal based on out-degree with on average 1.4% removed holdings, followed by outgoing infection chain and outgoing closeness. The targeted removal using the betweenness centrality differed the most from the optimal combination in comparison to the other parameters which consider the outgoing trade contacts. Due to the pyramidal structure and the directed nature of the pork supply chain the most efficient interruption of the infection chain for all three time periods was obtained by using the targeted removal based on out-degree.
THE ROLE OF SUPPLY CHAIN COLLABORATION ON SUSTAINABLE SUPPLY CHAIN MANAGEMENT PERFORMANCE
Ince, Huseyin; Ince, Andac Sahinbey
2015-01-01
Sustainable supply chain management and collaboration have taken big attention from academicians and practitioners. The extensive literature review is conducted to analyse the relationship between Sustainable Supply Chain Management and collaboration and its effects on performance of SSCM dimensions. Then, a framework is proposed to explain the relationship between sustainable supply chain management and collaboration. For further studies the proposed framework should be tested empirically.
Chain-modified radioiodinated fatty acids
International Nuclear Information System (INIS)
Otto, C.A.
1987-01-01
Several carbon chain manipulations have been studied in terms of their effects on myocardial activity levels and residence time. The manipulations examined included: chain length, chain branching, chain unsaturation, and carbon-iodine bond stabilization. It was found that chain length affects myocardial activity levels for both straight-chain alkyl acids and branched chain alkyl and aryl acids. Similar results have been reported for the straight-chain aryl acids. Generally, the longer chain lengths correlated with higher myocardial activity levels and longer residence times. This behavior is attributed to storage as triglycerides. Branched chain acids are designed to be anti-metabolites but only the aryl β-methyl acids possessed the expected time course of constant or very slowly decreasing activity levels. The alkyl β-methyl acids underwent rapid deiodination - a process apparently independent of β-oxidation. Inhibition of β-oxidation by incorporation of carbon-carbon double and triple bonds was studied. Deiodination of ω-iodo alkyl fatty acids prevented an assessment of suicide inhibition using an unsaturated alkynoic acid. Stabilization of the carbon-iodine bond by attachment of iodine to a vinylic or aryl carbon was studied. The low myocardial values and high blood values observed for an eleven carbon ω-iodo vinylic fatty acid were not encouraging but ω-iodo aryl fatty acids appear to avoid the problems of rapid deiodination. (Auth.)
The exactly solvable spin Sutherland model of BN type and its related spin chain
International Nuclear Information System (INIS)
Basu-Mallick, B.; Finkel, F.; González-López, A.
2013-01-01
We compute the spectrum of the su(m) spin Sutherland model of B N type, including the exact degeneracy of all energy levels. By studying the large coupling constant limit of this model and of its scalar counterpart, we evaluate the partition function of their associated spin chain of Haldane–Shastry type in closed form. With the help of the formula for the partition function thus obtained we study the chain's spectrum, showing that it cannot be obtained as a limiting case of its BC N counterpart. The structure of the partition function also suggests that the spectrum of the Haldane–Shastry spin chain of B N type is equivalent to that of a suitable vertex model, as is the case for its A N−1 counterpart, and that the density of its eigenvalues is normally distributed when the number of sites N tends to infinity. We analyze this last conjecture numerically using again the explicit formula for the partition function, and check its validity for several values of N and m.
An efficient algorithm to perform local concerted movements of a chain molecule.
Directory of Open Access Journals (Sweden)
Stefano Zamuner
Full Text Available The devising of efficient concerted rotation moves that modify only selected local portions of chain molecules is a long studied problem. Possible applications range from speeding the uncorrelated sampling of polymeric dense systems to loop reconstruction and structure refinement in protein modeling. Here, we propose and validate, on a few pedagogical examples, a novel numerical strategy that generalizes the notion of concerted rotation. The usage of the Denavit-Hartenberg parameters for chain description allows all possible choices for the subset of degrees of freedom to be modified in the move. They can be arbitrarily distributed along the chain and can be distanced between consecutive monomers as well. The efficiency of the methodology capitalizes on the inherent geometrical structure of the manifold defined by all chain configurations compatible with the fixed degrees of freedom. The chain portion to be moved is first opened along a direction chosen in the tangent space to the manifold, and then closed in the orthogonal space. As a consequence, in Monte Carlo simulations detailed balance is easily enforced without the need of using Jacobian reweighting. Moreover, the relative fluctuations of the degrees of freedom involved in the move can be easily tuned. We show different applications: the manifold of possible configurations is explored in a very efficient way for a protein fragment and for a cyclic molecule; the "local backbone volume", related to the volume spanned by the manifold, reproduces the mobility profile of all-α helical proteins; the refinement of small protein fragments with different secondary structures is addressed. The presented results suggest our methodology as a valuable exploration and sampling tool in the context of bio-molecular simulations.
DEFF Research Database (Denmark)
Grønholdt, Lars; Martensen, Anne
2016-01-01
This paper examines the links between employee attitudes, customer loyalty and company profitability. From a conceptual point of view, this employee-customer-profit chain, also known as the service-profit chain, is well founded and generally accepted. But for many companies, it seems difficult...... to demonstrate such links, and several issues must be addressed to uncover the links. To investigate these links empirically, a hotel chain provided data matching employee and customer measures with measures of profitability. We have successfully employed a modeling approach, and the paper reports empirical...... evidence of the employee-customer-profit chain. As it is possible to estimate the links, we have demonstrated their effect on company profitability. The research findings provide a better understanding of the service-profit chain and may help practitioners in improving company financial performance....
DEFF Research Database (Denmark)
Baxter, John; Wahlstrom, Margareta; Zu Castell-Rüdenhausen, Malin
2014-01-01
Optimizing plastic value chains is regarded as an important measure in order to increase recycling of plastics in an efficient way. This can also lead to improved awareness of the hazardous substances contained in plastic waste, and how to avoid that these substances are recycled. As an example......, plastics from WEEE is chosen as a Nordic case study. The project aims to propose a number of improvements for this value chain together with representatives from Nordic stakeholders. Based on the experiences made, a guide for other plastic value chains shall be developed....
DEFF Research Database (Denmark)
Rolstadås, Asbjørn; Pinto, Jeffrey K.; Falster, Peter
2015-01-01
To add value to project performance and help obtain project success, a new framework for decision making in projects is defined. It introduces the project decision chain inspired by the supply chain thinking in the manufacturing sector and uses three types of decisions: authorization, selection......, and plan decision. A primitive decision element is defined where all the three decision types can be accommodated. Each task in the primitive element can in itself contain subtasks that in turn will comprise new primitive elements. The primitive elements are nested together in a project decision chain....
Essentials of supply chain management
Hugos, Michael H
2011-01-01
The latest thinking, strategies, developments, and technologies to stay current in supply chain management Presenting the core concepts and techniques of supply chain management in a clear, concise and easily readable style, the Third Edition of Essentials of Supply Chain Management outlines the most crucial tenets and concepts of supply chain management.
Single-Chain Conformation for Interacting Poly(N-isopropylacrylamide in Aqueous Solution
Directory of Open Access Journals (Sweden)
Boualem Hammouda
2015-04-01
Full Text Available The demixing phase behavior of Poly(N-isopropylacrylamide (PNIPAM aqueous solution is investigated using small-angle neutron scattering. This polymer phase separates upon heating and demixes around 32 °C. The pre-transition temperature range is characterized by two scattering modes; a low-Q (large-scale signal and a high-Q dissolved chains signal. In order to get insight into this pre-transition region, especially the origin of the low-Q (large-scale structure, the zero average contrast method is used in order to isolate single-chain conformations even in the demixing polymers transition region. This method consists of measuring deuterated and non-deuterated polymers dissolved in mixtures of deuterated and non-deuterated water for which the polymer scattering length density matches the solvent scattering length density. A fixed 4% polymer mass fraction is used in a contrast variation series where the d-water/h-water fraction is varied in order to determine the match point. The zero average contrast (match point sample displays pure single-chain scattering with no interchain contributions. Our measurements prove that the large scale structure in this polymer solution is due to a transient polymer network formed through hydrophobic segment-segment interactions. Scattering intensity increases when the temperature gets close to the phase boundary. While the apparent radius of gyration increases substantially at the Lower Critical Solution Temperature (LCST transition due to strong interchain correlation, the single-chain true radius of gyration has been found to decrease slightly with temperature when approaching the transition.
A remark on Dickey's stabilizing chain
International Nuclear Information System (INIS)
Svinin, Andrei K.
2011-01-01
We observe that Dickey's stabilizing chain can be naturally included into two-dimensional chain of infinitely many copies of equations of KP hierarchy. -- Highlights: → In this study we consider Dickey's stabilizing chain. → We construct two-dimensional chain of dressing truncated operators. → We show that Dickey's stabilizing chain can be included into two-dimensional chain of KP hierarchies.
Branched-chain and aromatic amino acid profiles and diabetes risk in Chinese populations
Tianlu Chen; Yan Ni; Xiaojing Ma; Yuqian Bao; Jiajian Liu; Fengjie Huang; Cheng Hu; Guoxiang Xie; Aihua Zhao; Weiping Jia; Wei Jia
2016-01-01
Recent studies revealed strong evidence that branched-chain and aromatic amino acids (BCAAs and AAAs) are closely associated with the risk of developing type 2 diabetes in several Western countries. The aim of this study was to evaluate the potential role of BCAAs and AAAs in predicting the diabetes development in Chinese populations. The serum levels of valine, leucine, isoleucine, tyrosine, and phenylalanine were measured in a longitudinal and a cross sectional studies with a total of 429 C...
Arabica Coffee Farming and Marketing Chain Analysis in Manggarai and EastManggarai Districts
Sophia Hartatri, Dhiany. Faila; de Rosari, Bernard
2011-01-01
Arabica coffee has a unique flavour and very potential market. The purpose of this study was to analyse Arabica coffee farming and to investigate its performance of marketing chains in Manggarai and East Manggarai Districts, Flores, East Nusa Tenggara Province. This research was conducted in 2008-2010 by interviewing coffee farmers and coffee buyers; using open and close questions. The number of respondents were 100 people in each district. The result showed that land holding per household fa...
Method of identification of unbranched chain reaction with cross termination of chain
International Nuclear Information System (INIS)
Poluehktov, V.A.; Begishev, I.R.
1977-01-01
Gas-phase chlorination of unsymmetrical difluoroethane initiated by gamma quanta of Co 60 has been studied. At decreased temperatures the only hydrogen is replaced by a chlorine atom. Over a wide range of ratios of the initial reagents, the reaction occurs with a chain rupture. An analysis of the kinetics of such a reaction provides a method for identification of an unbranched chain reaction with a cross-rupture of the chain
Risikobasiertes Supply-Chain-Management
DEFF Research Database (Denmark)
Wieland, Andreas; Schinz, Philipp
2015-01-01
Das Management erlebt seit einigen Jahren dahingehend einen Paradigmenwechsel, dass nicht mehr Unternehmen als einzelne autonome Einheiten im Wettbewerb zueinander stehen, sondern die Supply Chains, in denen diese Unternehmen eingebunden sind. Ursachen hierfür sind beispielsweise die Auslagerung...... von Nicht-Kernprozessen auf vorgelagerte Stufen der Supply Chain oder auf Supply-Chain-Dienstleister sowie die Internationalisierung der Beschaffung. Dieser Paradigmenwechsel hat traditionelles Denken in den Schranken des Systems „Unternehmen“ abgelöst und zum Supply- Chain-Denken geführt, das vor......- und nachgelagerte Stufen des Systems „End-to-End-Supply-Chain“ einbezieht, etwa auch die Lieferanten von Lieferanten....
Concurrent Product & Supply Chain Creation
DEFF Research Database (Denmark)
Gubi, Ebbe
it is a structural premise. We also know that logistics costs generally are estimated 15-20% of total product costs. Accordingly, it stands to reason that a company can reduce costs, and thereby gain an edge on its competitors, by tailoring the supply chain in question to an individual product or product family; i.......e. by creating Focused Supply Chains. At the same time, customer satisfaction can be increased. As a second means to achieving a better fit between product and supply chain, the firm can deploy Design for Logistics, the discipline of considering the supply chain during product creation. The thesis sets out...... and supply chains should be created concurrently and integrated. The concept of Concurrent Product & Supply Chain Creation is introduced, and the two main components Focused Supply Chains and Design For Logistics are explained and exemplified by use of Bang & Olufsen....
Risk Management in Biopharmaceutical Supply Chains
Ma, Yao
2011-01-01
Biopharmaceutical supply chains present considerable complexity issue for the formulation of optimal plans due to significant uncertainty in the supply chain. The primary goal of biopharmaceutical supply chain planning is to provide reliable supply to patients while coping with various supply chain risks. In chapter 1 first I discuss the key elements and basic characteristics of the biopharmaceutical supply chain . Then I present the major challenges in biopharmaceutical supply chain planning...
Halalan Toyyiban Supply Chain The New Insights in Sustainable Supply Chain Management
Omar, Emi Normalina; Jaafar, Harlina Suzana; Osman, Muhamad Rahimi; Nasruddin, Faisol
2013-01-01
Purpose: In today’s highly competitive world scenario, in order for logistics and supply chain firms to be successful, resilient and sustainable, halalan-toyyiban supply chain could be the new insight in assisting the firm. Hence, the purpose of this study is to provide a practical definition for developing an effective supply chain through halalan toyyiban processes and comparing the similarities and differences of the halal term. Design/methodology/approach: The analysis is develo...
The Tax-Efficient Supply Chain
DEFF Research Database (Denmark)
Webber, Stuart
2011-01-01
Many multinational enterprises are restructuring supply chains to reduce their cost structures. As trade barriers fall and communications technologies improve, it has become easier and more cost-effective to manage business operations across international borders. This has motivated businesses...... practitioners in France, South Africa, Switzerland, Mexico, Argentina, and the United States. Companies are restructuring their supply chains and simultaneously reducing their income tax obligations. This article demonstrates that MNEs should link income tax and supply chain considerations when restructuring...... their supply chains, and they should endeavor to maximize net income when doing so. This recommendation differs from the great majority of supply chain literature, which has generally recommended that businesses seek to minimize pretax costs. One of the most important activities for both supply chain and tax...
1984-01-01
Two variants in immunoglobulin heavy chain production, derived from the MPC 11 mouse myeloma cell line, make short heavy (H) chains with identical precise deletions of the CH3 domain. The CH3 domain is expressed in the H chain mRNA from both variants. Although in vitro translation of this mRNA produces one H chain species, deleted heavy chains are secreted as heavy-light (HL) and H2L2 moieties in contrast to MPC 11, which secretes only H2L2 . The heavy chains of HL apparently contain more car...
Supply chain dynamics in healthcare services.
Samuel, Cherian; Gonapa, Kasiviswanadh; Chaudhary, P K; Mishra, Ananya
2010-01-01
The purpose of this paper is to analyse health service supply chain systems. A great deal of literature is available on supply chain management in finished goods inventory situations; however, little research exists on managing service capacity when finished goods inventories are absent. System dynamics models for a typical service-oriented supply chain such as healthcare processes are developed, wherein three service stages are presented sequentially. Just like supply chains with finished goods inventory, healthcare service supply chains also show dynamic behaviour. Comparing options, service reduction, and capacity adjustment delays showed that reducing capacity adjustment and service delays gives better results. The study is confined to health service-oriented supply chains. Further work includes extending the study to service-oriented supply chains with parallel processing, i.e. having more than one stage to perform a similar operation and also to study the behaviour in service-oriented supply chains that have re-entrant orders and applications. Specific case studies can also be developed to reveal factors relevant to particular service-oriented supply chains. The paper explains the bullwhip effect in healthcare service-oriented supply chains. Reducing stages and capacity adjustment are strategic options for service-oriented supply chains. The paper throws light on policy options for managing healthcare service-oriented supply chain dynamics.
DEFF Research Database (Denmark)
Wieland, Andreas; Handfield, Robert B.
Supply chain management has made great strides in becoming a discipline with a standalone body of theories. As part of this evolution, researchers have sought to embed and integrate observed supply chain management phenomena into theoretical statements. In our review, we explore where we have been...
Novel spin excitation in the high field phase of an S=1 antiferromagnetic chain
International Nuclear Information System (INIS)
Hagiwara, M.; Kashiwagi, T.; Kimura, S.; Honda, Z.; Kindo, K.
2007-01-01
We report the results of high-field multi-frequency ESR experiment on the S=1 Heisenberg antiferromagnetic chain Ni(C 5 H 14 N 2 ) 2 N 3 (PF 6 ) for the fields up to about 55T and the frequencies up to about 2THz. We have found that excitation branches above the critical field (H c ) where the energy gap closes change into one branch around 15T which becomes close to the paramagnetic line at high fields. The branch above 15T fits well the conventional antiferromagnetic resonance mode with easy planar anisotropy. We compare the results with those in a weakly coupled antiferromagnetic dimer compound KCuCl 3 and discuss the origin of the branches observed above H c
Extending and Characterizing an Exoplanet System in a Pristine Chain of Resonances
Christiansen, Jessie; Gorjian, Varoujan; Hardegree-Ullman, Kevin; Livingston, John; Dressing, Courtney; Barclay, Thomas; Lintott, Chris; Ciardi, David; Barentson, Geert; Kristiansen, Martti; Crossfield, Ian; Benneke, Bjorn; Howard, Andrew
2018-01-01
The K2-138 (EPIC 245950175; 2MASS J23154776-1050590) exoplanet system was recently identified in the K2 mission campaign 12 data (Christiansen et al. 2018). The moderately bright (K=10.3) K1V star hosts at least five sub-Neptune planets (1.6-3.3 Re) in a compact configuration, all with periods shorter than 13 days. The five confirmed planets in the system form an unbroken chain of near first-order mean motion resonances, with each successive pair of planets having close to a 3:2 commensurability; this is the longest such chain as yet discovered. The K2 data contain two additional transits which, if confirmed as due to a sixth planet, could extend the chain even further. Due to the proximity of the K2-138 planets to mean motion resonances, it is an ideal target to search for transit timing variations (TTVs). In order to further both of these time-critical and important science cases, we propose for DDT time to capture a third transit of the candidate sixth planet, and also observe a chance nearby cluster of three transits of planets b, c, and d. (12hr for the 6th planet was approved.)
Closed string field theory: Quantum action and the Batalin-Vilkovsky master equation
International Nuclear Information System (INIS)
Zwiebach, B.
1993-01-01
The complete quantum theory of covariant closed strings is constructed in detail. The nonpolynomial action is defined by elementary vertices satisfying recursion relations that give rise to Jacobi-like identities for an infinite chain of string field products. The genus zero string field algebra is the homotopy Lie algebra L ∞ encoding the gauge symmetry of the classical theory. The higher genus algebraic structure implies the Batalin-Vilkovisky (BV) master equation and thus consistent BRST quantization of the quantum action. From the L ∞ algebra, and the BV equation on the off-shell state space we derive the L ∞ algebra, and the BV equation on physical states that were recently constructed in d=2 string theory. The string diagrams are surfaces with minimal area metrics, foliated by closed geodesics of length 2π. These metrics generalize quadratic differentials in that foliation bands can cross. The string vertices are succinctly characterized; they include the surfaces whose foliation bands are all of height smaller than 2π. (orig.)
DEFF Research Database (Denmark)
Wæhrens, Brian Vejrum; Slepniov, Dmitrij
2015-01-01
This workbook is recommended for the attention of students of and managers in Danish small and medium sized enterprises (SMEs). Danish SMEs are currently facing a number of key challenges related to their position in global value chains. This book provides an insight into value chain management t...
Crystallisation and chain conformation of long chain n-alkanes
International Nuclear Information System (INIS)
Gorce, J.
2000-06-01
Hydrocarbon chains are a basic component in a number of systems as diverse as biological membranes, phospholipids and polymers. A better understanding of the physical properties of n-alkane chains should provide a better understanding of these more complex systems. With this aim, vibrational spectroscopy has been extensively used. This technique, sensitive to molecular details, is the only one able to both identify and quantify conformational disorder present in paraffinic systems. To achieve this, methyl deformations have been widely used as ''internal standards'' for the normalisation of peak areas. However, in the case of n-alkanes with short chain length, such as n-C 44 H 90 for example, the infrared spectra recorded at liquid nitrogen temperature and reported here show the sensitivity of these latter peaks to the various crystal structures formed. Indeed, the main frequencies of the symmetric methyl bending mode were found between 1384 cm -1 and 1368 cm -1 as a function of the crystal form. Changes in the frequency of the first order of the L.A.M. present in the Raman spectra were also observed. At higher temperatures, non all-trans conformers, inferred from different infrared bands present in the wagging mode region, were found to be essentially placed at the end of the n-alkane chains. At the monoclinic phase transition, the concentration of end-gauche conformers, proportional to the area of the infrared band at 1342 cm -1 , increases abruptly. On the contrary, in the spectra recorded at liquid nitrogen temperature no such band is observed. We also studied the degree of disorder in two purely monodisperse long chain n-alkanes, namely n-C 198 H 398 and n-C 246 H 494 . The chain conformation as well as the tilt angle of the chains from the crystal surfaces were determined by means of low frequency Raman spectroscopy and S.A.X.S. measurements on solution-crystallised samples. The increase in the number of end-gauche conformers which was expected to occur with
The effect of chain flexibility and chain mobility on radiation crosslinking reactions of polymers
International Nuclear Information System (INIS)
Sun Jiazhen
2003-01-01
Flexibility of polymer chains is an important factor to effects of radiation crosslinking of the polymer. Polymers with flexible chains are easier to be crosslinked, with lower dose of gelation, than polymers with more rigid chains. And it is known that most polymers with abnormal rigidity can be radiation-crosslinked only at high temperatures when the molecular chains get enough mobility. The flexibility of polymer chains also influences the relationship between degree of degradation and radiation dose. A chain flexibility factor β has been introduced to modify the Charlesby-Pinner equation of sol-fraction and radiation dose. The new relationship equation applies to a wider range of polymers in radiation crosslinking. Studies also show that for flexible polymers with lower T g and molecular internal rotating factor, mechanism of radiation crosslinking is mainly in H type, whereas for rigid polymers with higher T g and molecular internal rotating factor, mechanism of radiation crosslinking is mainly in T type
Collaboration and Evolution of E-Commerce and Express Delivery Industry Supply Chain
Directory of Open Access Journals (Sweden)
Ying Xu
2016-01-01
Full Text Available Considering the contradictions between the electronic commerce (e-commerce and its matching express delivery service, this paper investigates a supply chain regarding e-commerce and express delivery industry, in which collaborative operations of enterprises are discussed. The profitability and collaboration capability acting as order parameters and the rest of the influential resources including logistics, fund, information, and commodity are selected with their interrelations being examined based on servo theory of synergetics. Besides, evolutionary model of the e-commerce and express delivery industry is established and analyzed according to self-organization method of system dynamic theory to illustrate order parameters’ role in system evolution, and numerical analyses emerged to intuitively demonstrate the solutions. We conclude the work along with its results of significant references for investigating resource integrations by combining the two closely related businesses in an entire cooperative supply chain and providing guidelines for e-commerce and express delivery enterprises and industries in effective collaboration and system evolution.
El Yazid Boudaren, Mohamed; Monfrini, Emmanuel; Pieczynski, Wojciech; Aïssani, Amar
2014-11-01
Hidden Markov chains have been shown to be inadequate for data modeling under some complex conditions. In this work, we address the problem of statistical modeling of phenomena involving two heterogeneous system states. Such phenomena may arise in biology or communications, among other fields. Namely, we consider that a sequence of meaningful words is to be searched within a whole observation that also contains arbitrary one-by-one symbols. Moreover, a word may be interrupted at some site to be carried on later. Applying plain hidden Markov chains to such data, while ignoring their specificity, yields unsatisfactory results. The Phasic triplet Markov chain, proposed in this paper, overcomes this difficulty by means of an auxiliary underlying process in accordance with the triplet Markov chains theory. Related Bayesian restoration techniques and parameters estimation procedures according to the new model are then described. Finally, to assess the performance of the proposed model against the conventional hidden Markov chain model, experiments are conducted on synthetic and real data.
Genes involved in long-chain alkene biosynthesis in Micrococcus luteus
Energy Technology Data Exchange (ETDEWEB)
Beller, Harry R.; Goh, Ee-Been; Keasling, Jay D.
2010-01-07
Aliphatic hydrocarbons are highly appealing targets for advanced cellulosic biofuels, as they are already predominant components of petroleum-based gasoline and diesel fuels. We have studied alkene biosynthesis in Micrococcus luteus ATCC 4698, a close relative of Sarcina lutea (now Kocuria rhizophila), which four decades ago was reported to biosynthesize iso- and anteiso branched, long-chain alkenes. The underlying biochemistry and genetics of alkene biosynthesis were not elucidated in those studies. We show here that heterologous expression of a three-gene cluster from M. luteus (Mlut_13230-13250) in a fatty-acid overproducing E. coli strain resulted in production of long-chain alkenes, predominantly 27:3 and 29:3 (no. carbon atoms: no. C=C bonds). Heterologous expression of Mlut_13230 (oleA) alone produced no long-chain alkenes but unsaturated aliphatic monoketones, predominantly 27:2, and in vitro studies with the purified Mlut_13230 protein and tetradecanoyl-CoA produced the same C27 monoketone. Gas chromatography-time of flight mass spectrometry confirmed the elemental composition of all detected long-chain alkenes and monoketones (putative intermediates of alkene biosynthesis). Negative controls demonstrated that the M. luteus genes were responsible for production of these metabolites. Studies with wild-type M. luteus showed that the transcript copy number of Mlut_13230-13250 and the concentrations of 29:1 alkene isomers (the dominant alkenes produced by this strain) generally corresponded with bacterial population over time. We propose a metabolic pathway for alkene biosynthesis starting with acyl-CoA (or -ACP) thioesters and involving decarboxylative Claisen condensation as a key step, which we believe is catalyzed by OleA. Such activity is consistent with our data and with the homology (including the conserved Cys-His-Asn catalytic triad) of Mlut_13230 (OleA) to FabH (?-ketoacyl-ACP synthase III), which catalyzes decarboxylative Claisen condensation during
Supply Chain Management for Improved Energy Efficiency: Review and Opportunities
Directory of Open Access Journals (Sweden)
Beatrice Marchi
2017-10-01
Full Text Available Energy efficiency represents a key resource for economic and social development, providing substantial benefits to different stakeholders, ranging from the entities which develop energy efficient measures to everyone in society. In addition to cost savings, multiple benefits can be achieved by supporting a better alignment between energy issues and strategic business priorities: e.g., improved competitiveness, profitability, quality, etc. Thus, energy efficiency can be a strategic advantage, not just a marginal issue, for companies. However, most firms, especially small and medium enterprises (SMEs, face many problems and, in some cases, hostility when trying to effectively implement energy efficiency actions. The most dominant barriers are the access to capital and the lack of awareness (especially in terms of life cycle cost effects. The supply chain viewpoint represents one of the main opportunities for overcoming those barriers and improving energy performance even for weaker companies. Since the current literature on energy efficiency and practical approaches to ensure energy efficiency mainly focus on energy performance on a single-firm basis, this paper aims to provide a systematic review of papers on the integration of energy efficiency in supply chain design and management published in academic journal, thereby defining potential research streams to close the gaps in the literature. A number of literature reviews have been published focusing on specific aspects of sustainable or on green supply chain management; however, to the best of our knowledge, no review has focused on the energy efficiency issue. Firstly, the present paper shows how considering energy consumption in supply chain management can contribute to more energy-efficient processes from a systemic point of view. Then, the review methodology used is defined and the sampled papers are analyzed and categorized based on the different approaches they propose. From these