Loading [MathJax]/jax/output/SVG/jax.js
Research article Special Issues

A Global Integration Platform for Optimizing Cooperative Modeling and Simultaneous Joint Inversion of Multi-domain Geophysical Data

  • This paper reviews the theoretical aspects and the practical issues of different types of geophysical integration approaches. Moreover it shows how these approaches can be combined and optimized into the same platform. We discuss both cooperative modeling and Simultaneous Joint Inversion (SJI) as complementary methods for integration of multi-domain geophysical data: these data can be collected at surface (seismic, electromagnetic, gravity) as well as in borehole (composite well logs). The main intrinsic difficulties of any SJI approach are the high computational requirements, the non-uniqueness of the final models, the proper choice of the relations between the different geophysical domains, the quantitative evaluation of reliability indicators. In order to face efficiently all these problems we propose and describe here a “systemic approach”: the algorithms of modeling and SJI are merged with an integration architecture that permits the selection of workflows and links between different algorithms, the management of data and models coming from different domains, the smart visualization of partial and final results. This Quantitative Integration System (QUIS) has been implemented into a complex software and hardware platform, comprising many advanced codes working in cooperation and running on powerful computer clusters. The paper is divided into two main parts. First we discuss the theoretical formulation of SJI and the key concepts of the QUIS platform. In the second part we present a synthetic SJI test and a case history of QUIS application to a real exploration problem.

    Citation: Dell’Aversana Paolo, Bernasconi Giancarlo, Chiappa Fabio. A Global Integration Platform for Optimizing Cooperative Modeling and Simultaneous Joint Inversion of Multi-domain Geophysical Data[J]. AIMS Geosciences, 2016, 2(1): 1-31. doi: 10.3934/geosci.2016.1.1

    Related Papers:

    [1] Li Cheng, Yi Zhang, Ying-Wu Hu . Linear superposition and interaction of Wronskian solutions to an extended (2+1)-dimensional KdV equation. AIMS Mathematics, 2023, 8(7): 16906-16925. doi: 10.3934/math.2023864
    [2] Yaqiong Liu, Yunting Li, Qiuping Liao, Yunhui Yi . Classification of nonnegative solutions to fractional Schrödinger-Hatree-Maxwell type system. AIMS Mathematics, 2021, 6(12): 13665-13688. doi: 10.3934/math.2021794
    [3] Yong-Chao Zhang . Least energy solutions to a class of nonlocal Schrödinger equations. AIMS Mathematics, 2024, 9(8): 20763-20772. doi: 10.3934/math.20241009
    [4] Amjad Hussain, Muhammad Khubaib Zia, Kottakkaran Sooppy Nisar, Velusamy Vijayakumar, Ilyas Khan . Lie analysis, conserved vectors, nonlinear self-adjoint classification and exact solutions of generalized $ \left(N+1\right) $-dimensional nonlinear Boussinesq equation. AIMS Mathematics, 2022, 7(7): 13139-13168. doi: 10.3934/math.2022725
    [5] Mahmoud Soliman, Hamdy M. Ahmed, Niveen Badra, M. Elsaid Ramadan, Islam Samir, Soliman Alkhatib . Influence of the $ \beta $-fractional derivative on optical soliton solutions of the pure-quartic nonlinear Schrödinger equation with weak nonlocality. AIMS Mathematics, 2025, 10(3): 7489-7508. doi: 10.3934/math.2025344
    [6] Zh. Myrzakulova, Z. Zakariyeva, K. Suleimenov, U. Uralbekova, K. Yesmakhanova . Explicit solutions of nonlocal reverse-time Hirota-Maxwell-Bloch system. AIMS Mathematics, 2024, 9(12): 35004-35015. doi: 10.3934/math.20241666
    [7] Wen-Xin Zhang, Yaqing Liu . Solitary wave solutions and integrability for generalized nonlocal complex modified Korteweg-de Vries (cmKdV) equations. AIMS Mathematics, 2021, 6(10): 11046-11075. doi: 10.3934/math.2021641
    [8] Weerawat Sudsutad, Wicharn Lewkeeratiyutkul, Chatthai Thaiprayoon, Jutarat Kongson . Existence and stability results for impulsive $ (k, \psi) $-Hilfer fractional double integro-differential equation with mixed nonlocal conditions. AIMS Mathematics, 2023, 8(9): 20437-20476. doi: 10.3934/math.20231042
    [9] Xinyi Zhang, Jian Zhang . On Schrödinger-Poisson equations with a critical nonlocal term. AIMS Mathematics, 2024, 9(5): 11122-11138. doi: 10.3934/math.2024545
    [10] Zeliha Korpinar, Mustafa Inc, Ali S. Alshomrani, Dumitru Baleanu . The deterministic and stochastic solutions of the Schrodinger equation with time conformable derivative in birefrigent fibers. AIMS Mathematics, 2020, 5(3): 2326-2345. doi: 10.3934/math.2020154
  • This paper reviews the theoretical aspects and the practical issues of different types of geophysical integration approaches. Moreover it shows how these approaches can be combined and optimized into the same platform. We discuss both cooperative modeling and Simultaneous Joint Inversion (SJI) as complementary methods for integration of multi-domain geophysical data: these data can be collected at surface (seismic, electromagnetic, gravity) as well as in borehole (composite well logs). The main intrinsic difficulties of any SJI approach are the high computational requirements, the non-uniqueness of the final models, the proper choice of the relations between the different geophysical domains, the quantitative evaluation of reliability indicators. In order to face efficiently all these problems we propose and describe here a “systemic approach”: the algorithms of modeling and SJI are merged with an integration architecture that permits the selection of workflows and links between different algorithms, the management of data and models coming from different domains, the smart visualization of partial and final results. This Quantitative Integration System (QUIS) has been implemented into a complex software and hardware platform, comprising many advanced codes working in cooperation and running on powerful computer clusters. The paper is divided into two main parts. First we discuss the theoretical formulation of SJI and the key concepts of the QUIS platform. In the second part we present a synthetic SJI test and a case history of QUIS application to a real exploration problem.



    Integrable evolution equations are very common and play a key role in nonlinear science, as shown in studies like [1,2,3]. Specifically, the Korteweg-de Vries (KdV) equation, which comes from fluid dynamics, explains how waves with slight dispersion and small amplitude evolve in media with quadratic nonlinearity [2,4]. Additionally, the nonlinear Schrödinger (NLS) equation describes the behavior of waves that are slightly nonlinear and quasi-monochromatic in media with cubic nonlinearity [3,5,6]. Moreover, the derivative nonlinear Schrödinger (DNLS) equation is used to describe Alfvén waves in plasmas with low-$ \beta $ values, as well as large-amplitude waves that run parallel to the magnetic field [7,8,9]. These equations are mathematically integrable, meaning they can be solved exactly.

    Recently, Ablowitz and Musslimani introduced the following parity time (PT)-symmetric nonlocal NLS equation and derived its explicit solutions[10]:

    $ iut(x,t)=uxx(x,t)+2εu(x,t)2u(x,t)(ε=±1), $ (1.1)

    where $ \varepsilon = \pm 1 $ denotes the focusing $ (+) $ and defocusing $ (-) $ nonlinearity, and the asterisk denotes the complex conjugate. The PT symmetry implies that the self-induced potential $ V(x, t) = u(x, t) u^{*}(-x, t) $ fulfills the relation $ V^{*}(-x, t) = V(x, t) $, while the nonlocality indicates that the value of the potential $ V(x, t) $ at $ x $ requires the information on $ u(x, t) $ at $ x $, as well as at $ -x $[11,12,13]. Since Eq (1.1) exhibits properties akin to those of the standard NLS equation, such as integrability in the Lax and inverse scattering senses, a significant amount of theoretical research has been conducted[14,15,16], and the study on the equations has extended to higher-order and coupled ones[17,18,19]. Furthermore, there has been experimental evidence observed in the fields of optics and materials science[20,21,22].

    Subsequently, some other nonlocal integrable equations have been proposed[23,24,25]. One of these nonlocal equations is the nonlocal DNLS equation[8,9],

    $ iut(x,t)=uxx(x,t)+ε[u(x,t)2u(x,t)]x(ε=±1), $ (1.2)

    which is obtained from the standard DNLS equation by replacing $ |u|^2 u $ with $ u(x, t)^2 u^{*}(-x, t) $, and the conserved density $ V(x, t) = u(x, t) u^{*}(-x, t) $ satisfies the relation $ V^{*}(-x, t) = V(x, t) $. In [8], hierarchies of nonlocal DNLS-type equations have been derived utilizing Lie algebra splitting, with the specific nonlocal DNLS equation being termed as nonlocal DNLSI. Zhou[9] formulates the 2n-fold Darboux transformation (DT) and derives global bounded solutions from zero seed solutions for Eq (1.2). In this paper, we concentrate on how to construct arbitrary order DT of Eq (1.2), what happens if the eigenvalues degenerate, and how to construct solutions from different seeds.

    This paper is organized as follows: In Section 2, we give a detailed derivation of the Wronskian-type determinant representation of arbitrary order DT. Moreover, different choice of the eigenvalues may lead different Darboux matrix, even in the same order. If there are duplicate eigenvalues, a generalized form of the DT may prove useful. In Section 3, we obtain solutions of Eq (1.2) from zero and non-zero seed solutions. Periodic solutions and rogue waves are constructed despite of the existence of singularity. Finally, conclusions and discussions are given in Section 4.

    In this section, we will construct the DT of the coupled nonlocal DNLS equations

    $ iutuxx+(u2v)x=0, $ (2.1a)
    $ ivt+vxx+(uv2)x=0, $ (2.1b)

    which is the compatibility condition of the following Lax pair [9]:

    $ Φx=UΦ,Φt=VΦ, $ (2.2)

    where $ \Phi = (f(x, t), g(x, t))^{T} $,

    $ U=λ2σ3+λP=(λ2λuλvλ2), $ (2.3)
    $ V=i(λ2uv2λ4)σ32iλ3P+iλ(P3σ3Px)=(iλ2uv2iλ4iλ(u2vux)2iλ3uiλ(uv2+vx)2iλ3viλ2uv+2iλ4), $ (2.4)

    with

    $ P=(0uv0), $ (2.5)

    and Pauli matrix

    $ σ3=(1001). $ (2.6)

    Under the reduction condition $ v(x, t) = -\varepsilon \bar{u}^{*}(x, t) = -\varepsilon u^{*}(-x, t) $, Eq (2.1) will be reduced to the nonlocal DNLS Eq (1.2). Here, $ \bar{f}(x, t) $ means $ f(-x, t) $. Unlike the local DNLS equation, there are four linear independence solutions of (2.2) associate with one complex eigenvalue. Specifically, if $ \left(fg \right) $ are solutions of (2.2) with $ \lambda $, then $ \left(fg \right) $, $ \left(εˉgˉf \right) $, and $ \left(εˉgˉf \right) $ are solutions of (2.2) with $ -\lambda $, $ \lambda^* $, and $ -\lambda^* $, respectively.

    We can suppose $ \Phi_{[1]} = T\Phi $ as the DT, where

    $ T=(λa1(x,t)+a0(x,t)λb1(x,t)+b0(x,t)λc1(x,t)+c0(x,t)λd1(x,t)+d0(x,t)) $ (2.7)

    is the first-order DT matrix, and there exist $ U_{[1]} $ and $ V_{[1]} $ possessing the same form as $ U $ and $ V $ with $ u $ and $ v $ replaced by the new potentials $ u_{[1]} $ and $ v_{[1]} $, which satisfy Eq (2.2). Therefore, $ T[\lambda] $ must satisfy conditions

    $ Tx+TUU[1]T=0, $ (2.8a)
    $ Tt+TVV[1]T=0. $ (2.8b)

    We set $ \Phi_1 = \left(f1g1 \right) $ are solutions of (2.2) with $ \lambda = \lambda_1 $. Comparing the coefficients of $ \lambda^j, (j = 3, 2, 1, 0) $ in Eq (2.8), we obtain $ b_1(x, t) = c_1(x, t) = a_0(x, t) = d_0(x, t) = 0 $, $ b_0(x, t) = b_0, c_0(x, t) = c_0 $ and $ a_1(x, t) = \frac{g_1}{ f_1}, d_1(x, t) = \frac{f_1}{ g_1} $ by setting $ b_0 = c_0 = -\lambda_1 $, so we have

    $ u[1]=ρ12u+2λ1ρ1, $ (2.9a)
    $ v[1]=1ρ12v2λ11ρ1, $ (2.9b)

    where $ \rho_1 = \frac{ g_1}{f_1} $.

    Theorem 1. Suppose $ \lambda_1\neq 0 $, which is real when $ \varepsilon = 1 $ or purely imaginary when $ \varepsilon = -1 $. Define $ \Phi_{[1]} $ and $ \rho_1 $ as above such that $ \rho_1 \bar{\rho_1}^* = 1 $. Then Eq (2.9) are new solutions of (1.2), and the corresponding Darboux matrix is

    $ T=(λρ1λ1λ1λρ1)=λ(ρ11ρ1)(λ1λ1). $ (2.10)

    Proof. We only need to prove $ v_{[1]} = -\varepsilon \bar{u}_{[1]}{}^* $, which can be easily verified by using (2.9) and $ \rho_1 \bar{\rho_1}^* 0. $

    As $ \lambda_1 $ will be real or purely imaginary, one-fold DT only allows two eigenvalues $ \lambda_1 $ and $ -\lambda_1 $, so one-fold DT is degenerated in a sense. If we choose $ \lambda_1 $, $ -\lambda_1 $, $ \lambda_1{}^* $, and $ -\lambda_1{}^* $ as four different eigenvalues, the real and imaginary part of $ \lambda_1 $ are both not equal to zero and we need to construct multi-fold DT.

    In this subsection, we will construct the two-fold DT of (1.2). The multi-fold DT can be iterated by the one-fold DT, so we set second-order Darboux matrix as

    $ T2=λ2(a21a2)+λ(b1c1)+(a0a0). $ (2.11)

    We set $ \Phi_k = \left(fkgk \right) $ are solutions of (2.2) with $ \lambda = \lambda_k $, $ \rho_k = \frac{ g_k}{f_k} (k = 1, 2) $, and then $ T_2 $ maps $ (u, v, \Phi) $ to $ (u_{[2]}, v_{[2]}, \Phi_{[2]}) $. By following the previous steps, we obtain

    $ u[2]=a22u2a2b1,v[2]=va22+2c1a2 $ (2.12)

    with

    $ a0=λ1λ2,a2=|λ1g1f1λ2g2f2||λ1f1g1λ2f2g2|,b1=|f1λ12f1f2λ22f2||λ1f1g1λ2f2g2|,c1=|g1λ12g1g2λ22g2||λ1g1f1λ2g2f2|. $ (2.13)

    If $ \lambda_2 = \lambda_1{}^* $ and $ \lambda_1{}^* \neq \pm \lambda_1 $, we can obtain Theorem 1 in [9]. Moreover, if $ \lambda_1, \lambda_2 $ are both real or purely imaginary, we can also obtain new solutions of (1.2).

    From above results, we know the DT will be iterated two times if $ \lambda $ is a complex eigenvalue and one times if $ \lambda $ is real or purely imaginary. Therefore, if we choose $ \lambda_k (k = 0, 1, 2, \cdot\cdot\cdot, n_1) $ as complex eigenvalues and $ \lambda_j (j = 0, 1, \cdot\cdot\cdot, n_2) $ as real $ (\varepsilon = 1) $ or purely imaginary $ (\varepsilon = -1) $ eigenvalues, then we can construct the $ (2n_1+n_2) $-fold DT of (1.2). For example, we can construct third-order DT by choosing $ (n_1, n_2) = (1, 1) $ or $ (0, 3) $ and fourth-order DT by choosing $ (n_1, n_2) = (2, 0) $, $ (1, 2) $, or $ (0, 4) $. Even though the $ 2n $-fold DT have been derived in [9] by choosing $ n_1 = n, n_2 = 0 $, we construct the Wronskian-type determinant representation of the Darboux matrix.

    $ 2n $-order DT

    We set $ 2n $-order Darboux matrix as

    $ T2n(λ)=λ2n(a2nd2n)+λ2n1(b2n1c2n1)++(a0d0), $ (2.14)

    and $ \Phi_k = \left(fkgk \right) $ are solutions of (2.2) with $ \lambda = \lambda_k $, $ \rho_k = \frac{ g_k}{f_k} \, (k = 1, 2, \cdots, 2n) $, and then $ T_{2n} $ maps $ (u, v, \Phi) $ to $ (u_{[2n]}, v_{[2n]}, \Phi_{[2n]}) $, where $ a_{2k}, d_{2k}\, (k = 0, 1, \cdots, n) $, $ b_{2k-1}, c_{2k-1} (k = 1, 2, \cdots, n) $ are $ 4n+2 $ unknown functions. Solving $ 4n $ equations $ T_{2n}(\lambda_k)\Phi_{[2n]} = 0 \, (k = 1, 2, \cdots, 2n) $ by setting $ d_{2n} = \frac{1}{a_{2n}} $ and $ d_0 = a_0 $, we can uniquely determine the $ 4n+2 $ unknown functions, and obtain

    $ u[2n]=a2n2u2a2nb2n1,v[2n]=va2n2+2c2n1a2n $ (2.15)

    with

    $ a2n=(1)na0D3D1,d2n=(1)na0D4D2,b2n1=a0D5D1,c2n1=a0D6D2, $ (2.16)

    and

    $ D1=|F(2,4,,2n)(1,2,,2n)G(1,3,,2n1)(1,2,,2n)|, $ (2.17a)
    $ D2=|F(1,3,,2n1)(1,2,,2n)G(2,4,,2n)(1,2,,2n)|, $ (2.17b)
    $ D3=|F(0,2,,2n2)(1,2,,2n)G(1,3,,2n1)(1,2,,2n)|, $ (2.17c)
    $ D4=|F(1,3,,2n1)(1,2,,2n)G(0,2,,2n2)(1,2,,2n)|, $ (2.17d)
    $ D5=|F(0,2,,2n)(1,2,,2n)G(1,3,,2n3)(1,2,,2n)|, $ (2.17e)
    $ D6=|F(1,3,,2n3)(1,2,,2n)G(0,2,,2n)(1,2,,2n)|, $ (2.17f)

    where

    $ F(2,4,,2n)(1,2,,2n)=[f1λ12f1λ14f1λ12nf2λ22f2λ24f2λ22nf2nλ2n2f2nλ2n4f2nλ2n2n], $ (2.18)
    $ G(1,3,,2n1)(1,2,,2n)=[g1λ1g1λ13g1λ12n1g2λ2g2λ23g2λ22n1g2nλ2ng2nλ2n3g2nλ2n2n1], $ (2.19)

    and other matrix blocks with the following blocks have been similarly defined.

    As $ D_1 = \prod_{j = 1}^{2n} \lambda_j D_4 $, $ D_2 = \prod_{j = 1}^{2n} \lambda_j D_3 $, and $ a_0 = \prod_{j = 1}^{2n} \lambda_j $, then $ d_{2n} = \frac{1}{a_{2n}} $ will be satisfied automatically.

    If we choose $ \lambda_{n+j} = \lambda_j^* $ and $ \Phi_{n+j} = \left(ε¯gj¯fj \right)\, (j = 1, 2, \cdots, n) $, then $ a_0 = \prod_{j = 1}^{n} |\lambda_j|^2 $, $ D_1 = |F(2,4,,2n)(1,2,,n)G(1,3,,2n1)(1,2,,n)εˉG(2,4,,2n)(1,2,,n)ˉF(1,3,,2n1)(1,2,,n)|\, $ and so are $ D_2, \cdots, D_6 $, where $ \bar{G}^{*(2, 4, \cdots, 2n)}_{(1, 2, \cdots, n)} $ means doing complex conjugate and space-reverse operation to $ G^{(2, 4, \cdots, 2n)}_{(1, 2, \cdots, n)} $.

    Theorem 2. Suppose $ \lambda_j \, (j = 1, 2, \cdots, n) $ are complex, which are all not real or purely imaginary. Then Eq (2.15) are new solutions of (1.2). Especially, when $ n = 1 $, (2.15) become (2.12).

    Proof. We only need to prove $ v_{[2n]} = -\varepsilon \bar{u}_{[2n]}{}^* $, which can be easily verified by using $ \bar{D_3}^* = D_4, $ and $ \bar{D_5}^* = \varepsilon D_6. $

    Remark 1. It is a little different if we choose $ \lambda_{k+j} = \lambda_j^* $, $ \Phi_{k+j} = \left(ε¯gj¯fj \right)\, (j = 1, 2, \cdots, k) $ and $ \lambda_{s}\, (s = 2k+1, \cdots, 2n) $ are all real $ (e.g., \varepsilon = 1) $, here $ a_0 = \prod_{j = 1}^{k} |\lambda_j|^2 \prod_{s = 2k+1}^{2n} \lambda_s $, $ D_1 = |F(2,4,,2n)(1,2,,k)G(1,3,,2n1)(1,2,,k)εˉG(2,4,,2n)(1,2,,k)ˉF(1,3,,2n1)(1,2,,k)F(2,4,,2n)(2k+1,,2n)G(1,3,,2n1)(2k+1,,2n)|\, $ and so are $ D_2, \cdots, D_6 $. Equation (2.15) is new solutions of (1.2) with constraints $ \rho_s \bar{\rho_s}^* = 1\, (s = 2k+1, \cdots, 2n) $.

    $ (2n-1) $-order DT

    We set $ (2n-1) $-order Darboux matrix as

    $ T2n1(λ)=(nk=1a2k1λ2k1n1k=0b2kλ2kn1k=0c2kλ2knk=1d2k1λ2k1), $ (2.20)

    and $ \Phi_k = \left(fkgk \right) $ are solutions of (2.2) with $ \lambda = \lambda_k $, $ \rho_k = \frac{ g_k}{f_k} \, (k = 1, 2, \cdots, 2n-1) $. Then $ T_{2n-1} $ maps $ (u, v, \Phi) $ to $ (u_{[2n-1]}, v_{[2n-1]}, \Phi_{[2n-1]}) $, where $ a_{2k-1}, d_{2k-1}\, (k = 1, 2, \cdots, n) $, $ b_{2k}, c_{2k} \, (k = 0, 1, \cdots, n-1) $ are $ 4n $ unknown functions. Solving $ 4n-2 $ equations $ T_{2n-1}(\lambda_k)\Phi_{[2n-1]} = 0 \, (k = 1, 2, \cdots, 2n-1) $ by setting $ d_{2n-1} = \frac{1}{a_{2n-1}} $ and $ c_0 = b_0 $, we can uniquely determine the $ 4n $ unknown functions, and obtain

    $ u[2n1]=a2n12u2a2n1b2n2,v[2n1]=va2n12+2c2n2a2n1 $ (2.21)

    with

    $ a2n1=b0D3D1,d2n1=b0D4D2,b2n2=(1)n1b0D5D1,c2n2=(1)n1b0D6D2, $ (2.22)

    where

    $ D1=|F(1,3,,2n1)(1,2,,2n1)G(2,4,2n2)(1,2,,2n1)|, $ (2.23a)
    $ D2=|F(2,4,,2n2)(1,2,,2n1)G(1,3,,2n1)(1,2,,2n1)|, $ (2.23b)
    $ D3=|F(1,3,,2n3)(1,2,,2n1)G(0,2,,2n2)(1,2,,2n1)|, $ (2.23c)
    $ D4=|F(0,2,,2n2)(1,2,,2n1)G(1,3,,2n3)(1,2,,2n1)|, $ (2.23d)
    $ D5=|F(1,3,,2n1)(1,2,,2n1)G(0,2,,2n4)(1,2,,2n1)|, $ (2.23e)
    $ D6=|F(0,2,,2n4)(1,2,,2n1)G(1,3,,2n1)(1,2,,2n1)|. $ (2.23f)

    Noticing $ D_1 = \prod_{j = 1}^{2n-1} \lambda_j D_4 $, $ D_2 = \prod_{j = 1}^{2n-1} \lambda_j D_3 $ and $ b_0 = -\prod_{j = 1}^{2n-1} \lambda_j $, then $ d_{2n} = \frac{1}{a_{2n}} $ will be satisfied automatically.

    If we choose $ \lambda_{k+j} = \lambda_j^* $ and $ \Phi_{k+j} = \left(ε¯gj¯fj \right)\, (j = 1, 2, \cdots, k) $, then $ b_0 = - \prod_{j = 1}^{k} |\lambda_j|^2 \prod_{s = 2k+1}^{2n-1} \lambda_{s} $, $ D_1 = |F(1,3,,2n1)(1,2,,k)G(2,4,,2n2)(1,2,,k)εˉG(1,3,,2n1)(1,2,,k)ˉF(2,4,,2n2)(1,2,,k)F(1,3,,2n1)(2k+1,2k+2,,2n1)G(2,4,,2n2)(2k+1,2k+2,,2n1)|\, $ and so are $ D_2, \cdots, D_6 $.

    Theorem 3. Suppose $ \lambda_j \, (j = 1, 2, \cdots, k) $ are complex, and $ \lambda_s \, (s = 2k+1, 2k+2, \cdots, 2n-1) $ are real when $ \varepsilon = 1 $ or purely imaginary when $ \varepsilon = -1 $, then Eq (2.21) is new solutions of (1.2) with constraints $ \rho_s \bar{\rho_s}^* = 1\, (s = 2k+1, \cdots, 2n-1) $. Especially, when $ n = 1 $, (2.21) become (2.9).

    Proof. Similarly, we only need to prove $ v_{[2n-1]} = -\varepsilon \bar{u}_{[2n-1]}{}^* $, which can be easily verified by using $ \bar{D_3}^* = (-1)^{(n^2-1)} \varepsilon^{n} D_4, $ and $ \bar{D_5}^* = (-1)^{(n^2-1)} \varepsilon^{n-1} D_6. $

    Until now, we have constructed the arbitrary DT of (1.2) with Wronskian-type determinant representation. Compared with [9], we have not only constructed the DT of arbitrary order, but also adopted a simpler and more feasible way.

    In this section, we will construct several explicit solutions of Eq (1.2).

    • If we set seed solution $ u = v = 0 $, then solution of (2.2) with $ \lambda = \lambda_k $ is $ \Phi_k = \left(fkgk \right) = \left(αkeθkβkeθk \right) $, where $ \theta_k = \lambda_k^2 x-2 i \lambda_k^4 t \, (k = 1, 2, \cdots) $. As $ \lambda_1 $ is real when $ \varepsilon = 1 $ or purely imaginary when $ \varepsilon = -1 $ in Theorem 1, background of the new solution of (1.2) will go to infinity, which appears meaningless.

    • If we set seed solution $ u = \rho e^{-\varepsilon \rho ^2 x +i \phi } $, the background will also go to infinity. So, we take $ u = \rho e^{i \phi } $ as the seed solution eclectically to avoid infinity of the background. Solution of (2.2) with $ \lambda = \lambda_k $ is $ \Phi_k = \left(fkgk \right) $, where

    $ fk=αkeθk+βkeθk,gk=λkeiϕρfk+eiϕλkρfkx $ (3.1)

    with $ \theta_k = \sqrt{\lambda_k^4-\lambda_k^2 \rho ^2 \varepsilon } \left[x-i t \left(2 \lambda_k^2+\rho ^2 \varepsilon \right)\right] $, $ \rho_k = \frac{ g_k}{f_k} $, $ \alpha_k $ and $ \beta_k \, (k = 1, 2, \cdots) $ are none-zero complex constants.

    Using Theorem 1, we obtain

    $ u[1]=eiϕ[β21ρ2ε+2α1β1(2λ21ρ2ε)e2θ1+α21ρ2εe4θ1]ρ[β1+α1e2θ1]2 $ (3.2)

    under the constraint

    $ |α1|2|β1|2=λ21ρ2ε+λ21(ρ2ελ21)λ21+ρ2ε+λ21(ρ2ελ21), $ (3.3)

    which means $ |\lambda _1| > |\rho| $. This solution has been shown in Figure 1, which displays the periodic one-soliton with $ \varepsilon = 1, \rho = 4, \lambda_1 = 5, \alpha _1 = 2, \beta _1 = 1 $, $ \phi = \pi $, and $ \varepsilon = -1, \rho = 4, \lambda_1 = -5i, \alpha _1 = 1/2, \beta _1 = 1 $, $ \phi = 0 $. However, there are periodic singularities in any case for $ \varepsilon $. The reason for the existence of the singularity may be that $ \theta_k $ in solution (3.1) is too complex. When $ \varepsilon $ takes the values of -1 and 1, respectively, eigenvalue $ \lambda $ will differ due to the constraints, which subsequently causes variations in other parameters. Additionally, we found that the positions of the singular points have changed.

    Figure 1.  The periodic one-soliton from (3.2) with (a) $ \varepsilon = 1, \rho = 4, \lambda_1 = 5, \alpha _1 = 2, \beta _1 = 1 $, $ \phi = \pi $, and (b) $ \varepsilon = -1, \rho = 4, \lambda_1 = -5i, \alpha _1 = 1/2, \beta _1 = 1 $, $ \phi = 0 $.

    When the eigenvalue $ \lambda_1 = \pm \rho \, (\varepsilon = 1) $ or $ \lambda_1 = \pm i \rho \, (\varepsilon = -1) $, the new solution will be complex constant and trivial, so we should resolve (2.2). Now, the solution of (2.2) $ (\varepsilon = 1) $ is $ \Phi_1 = \left(f1g1 \right) $, where

    $ f1=α1+α2(x3iρ2t),g1=eiϕf1eiϕρ2f1x $ (3.4)

    with $ \alpha _k \, (k = 1, 2) $ are none-zero complex constants. We can obtain a new fundamental rational solution,

    $ u[1]=eiϕ[α21ρ4+α22(9ρ8t26iρ6tx+ρ4x21)+2α1α2ρ4(x3iρ2t)]ρ3[α1+α2(x3iρ2t)]2. $ (3.5)

    The graph of this solution is displayed in Figure 2(a) with $ \rho = 1, \alpha _1 = 1, \alpha _2 = 2 $ and $ \phi = \pi $. It is seen that this is a rogue wave, similar to Eq (40) in Yang's article[26], which blows up to infinity at $ x = -1/2 $ and finite time $ t = 0 $. Furthermore, rising from a constant background, rogue wave (3.5) can be considered as resulting from the degradation of periodic soliton (3.2). If we set $ \varepsilon = -1 $, then new rogue wave will blow up to infinity at $ x = 1/2 $ and $ t = 0 $, which is shown in Figure 2(b). Similarly, variations in the value of parameter $ \varepsilon $ only affects the position of solitons or rogue waves, without altering the type or mechanical properties of the solutions. Meanwhile, parameter $ \phi $ do not affect the modulus of the solutions.

    Figure 2.  The one rogue wave from (3.5) with (a) $ \varepsilon = 1, \rho = 1, \lambda_1 = -1, \alpha _1 = 1, \alpha _2 = 2 $, $ \phi = \pi $, and (b) $ \varepsilon = -1, \rho = 1, \lambda_1 = -i, \alpha _1 = -2, \alpha _2 = 4 $, $ \phi = 0 $.

    • When we set seed solution $ u = v = 0 $, the background of new solutions will not go to infinity if and only if $ \lambda^2 $ is pure imaginary, which means $ 4 arg\lambda/ \pi $ is an odd integer [9]. Hence, we can obtain a new soliton solution with $ \lambda_1 = a(1-i) $,

    $ u[2]=(4+4i)εaα1β1e4ia2(4a2t+x)(α1α1+iεβ1β1e8ia2x)(εβ1β1e8ia2x+iα1α1)2. $ (3.6)

    This solution does not have singularity and global if $ |\alpha _1| \neq |\beta_1| $, which is periodic in both $ x $ and $ t $. The graph is displayed in Figure 3 with $ \varepsilon = -1, a = 1, \alpha _1 = 1 $ and $ \beta _1 = 2 $, from which we can see that the norm of the solution is periodic in $ x $ but independent of $ t $. However, if $ \lambda_1 $ and $ \lambda_2 $ are both real or purely imaginary, the background of new solution will go to infinity.

    Figure 3.  Left panel is the periodic two solitons from (3.6) with $ \varepsilon = -1, \lambda_1 = 1-i, \alpha _1 = 1 $ and $ \beta _1 = 2 $; Right panel is the corresponding density plot.

    • If we set seed solution $ u = \rho e^{-\varepsilon \rho ^2 x +i \phi } $, the background will go to infinity. So, we take $ u = \rho e^{i \phi } $ as the seed solution, and the solution of (2.2) with $ \lambda = \lambda_k $ is (3.1). Using Eq (2.12), we can obtain new solutions of Eq (1.2) and display it in Figure 4. Figure 4 show the propagation of two solitons, the interaction of which seems elastic. However, the solution blows up to infinity in the interaction region at one fixed point. The reason for the existence of singularity may be due to nonlocal effects. Figure 5(a) shows the interaction of two periodic soliton with periodic singularities, as long as $ \lambda_1, \lambda_2 $ are both real numbers. This solution seems to be a superposition and interaction of two solutions (3.2). Furthermore, if $ \lambda_1 = \pm \rho $, then we can see that the interaction of periodic soliton and rogue wave, which has been shown in Figure 5(b), will degenerate into the seed solution if $ \lambda_2 = \pm \rho $.

    Figure 4.  Left panel is the interaction of two solitons from (2.12) with $ \varepsilon = 1, \rho = 1, \lambda_1 = (1+i\sqrt{3})/2, \alpha _1 = 1, \beta_1 = i, \phi = 0 $; Right panel is the corresponding density plot.
    Figure 5.  (a) Inteaction of two periodic solitons from (2.12) with $ \varepsilon = 1, \rho = 1, \lambda_1 = 2 $, $ \lambda_2 = 3, \alpha _1 = \sqrt{\frac{2\sqrt{3}+3}{2\sqrt{3}-3}}, \alpha _2 = \sqrt{\frac{6\sqrt{2}+8}{6\sqrt{2}-8}}, \; \beta_1 = \beta_2 = 1, \; \phi = 0 $; (b) Interaction of one periodic soliton and rogue wave from (2.12) with $ \varepsilon = 1, \rho = 1, \lambda_1 = -1, \lambda_2 = 2, \alpha _1 = 1+i, \alpha _2 = \sqrt{\frac{2\sqrt{3}+3}{2\sqrt{3}-3}}, \beta_1 = 2, \beta_2 = 1, \phi = 0 $.

    • Considering the third-order DT, three eigenvalues can be one complex and one real (or pure imaginary), or three real. New solutions derived from seeds $ u = \rho e^{i \phi } $ would be the superposition of previous solutions (2.9) and (2.12). For example, if we choose three eigenvalues as one complex and one real, new solutions is displayed in Figure 6(a). We can see Figure 6(a) is a superposition and interaction of Figure 1(a) and Figure 4. There is one periodic soliton and two elastic-interacted solitons. If the real eigenvalue equals $ \pm \rho $, then the solution will be different from Figure 6(a), which is shown in Figure 6(b). The phases of the solitons undergo changes, and two of them remain parallel both before and after the collision.

    Figure 6.  Interaction of three solitons from (2.21) with (a) $ \varepsilon = 1, \rho = 1, \lambda_1 = (1+i \sqrt{3})/2, \lambda_2 = 2, \alpha _1 = -1, \alpha _2 = \sqrt{\frac{2\sqrt{3}+3}{2\sqrt{3}-3}}, \beta_1 = \beta_2 = 1, \phi = 0 $; (b) $ \varepsilon = 1, \rho = \lambda_1 = 1, \lambda_2 = (1+i \sqrt{3})/2, \alpha _1 = \alpha _2 = \beta_1 = \beta_2 = 1, \phi = 0 $; (c) $ \varepsilon = 1, \rho = 1, \lambda_1 = 2, \lambda_2 = 3 $, $ \lambda_3 = 4 $, $ \alpha _1 = \sqrt{\frac{2\sqrt{3}+3}{2\sqrt{3}-3}}, \alpha _2 = \sqrt{\frac{6\sqrt{2}+8}{6\sqrt{2}-8}}, \alpha _3 = \sqrt{\frac{4\sqrt{15}+15}{4\sqrt{15}-15}}, \beta_1 = \beta_2 = \beta_3 = 1, \phi = 0 $; (d) $ \varepsilon = 1, \rho = 1 $, $ \lambda_1 = -1, \lambda_2 = 2, \lambda_3 = 2, \alpha _1 = 1, \alpha _2 = \sqrt{\frac{2\sqrt{3}+3}{2\sqrt{3}-3}}, \alpha _3 = \sqrt{\frac{6\sqrt{2}+8}{6\sqrt{2}-8}}, \beta_1 = 2, \beta_2 = \beta_3 = 1, \phi = 0 $.

    If three eigenvalues are all selected real, then the new solution is displayed in Figure 6(c), which are three times superposition and interaction of Figure 1(a). Further more, if one of three real eigenvalues equals $ \pm\rho $, then there will be a rogue wave, which has been shown in Figure 6(d).

    • Considering the fourth-order DT, we choose zero seed solutions and two complex eigenvalues $ \lambda_1 $, $ \lambda_2 $, where $ \lambda_k^2 (k = 1, 2) $ is pure imaginary to avoid infinity of the background. If $ \lambda_2 \neq \lambda_1 $, we can obtain periodic solitons, which have been shown in Figure 7. If $ \lambda_2 = \lambda_1 $, then solution of (2.2) with $ \lambda = \lambda_2 $, says $ \Phi_2 $, will linearly dependent on $ \Phi_1 $. Following the idea of generalized DT in [7], we set $ \Phi_1^{[1]} = \Phi_1(\lambda_1+\delta), \delta\ll1 $, and obtain

    $ Φ2=limδ0Φ1(λ1+δ)Φ1(λ1)δ, $ (3.7)

    which is another solution of (2.2) with $ \lambda = \lambda_1 $ but linearly independent on $ \Phi_1 $. Using (2.15), we obtain new solutions of (1.2),

    $ (4+4i)(64te8ix64itie8ix8e8ixx8ix1)(4096it2e8ix+128te8ix+64ie8ixx2ie8ix+e16ix1)e16it4ix(4096it2e8ix+128te8ix64ie8ixx2+ie8ix+e16ix1)2 $ (3.8)

    with $ \varepsilon = 1, \alpha _1 = \beta _1 = 1 $. This solution is a mixed-type of exponential and rational functions, whose norm is displayed in Figure 8. From it we can see there are three solitons, one $ x $-periodic soliton and two elastic-interacted solitons, and no rogue waves are presented obviously. However, the interaction blows up to infinity at two fixed points. As it has been seen that higher order solution can be the superposition and interaction of the lower order solution, we do not show the solutions derived from four real eigenvalues or one complex and two real eigenvalues. At the end, we display new periodic solitons in Figure 9 obtained by using six-order DT from zero seeds.

    Figure 7.  Left panel is the periodic four solitons from (2.15) with $ \varepsilon = 1, \lambda_1 = 1+i $, $ \lambda_2 = 2 (1-i) $, $ \alpha _1 = \alpha_2 = 1/5 $ and $ \beta _1 = \beta_2 = 1 $; Right panel is the corresponding density plot.
    Figure 8.  Left panel is interaction of three solitons from (3.8) with $ \varepsilon = 1, \lambda_1 = \lambda_2 = 1+i, \alpha _1 = \beta _1 = 1 $; Right panel is the corresponding density plot.
    Figure 9.  Left panel is interaction of periodic multi-solitons from (2.15) (n = 3) with $ \varepsilon = 1 $, $ \lambda_1 = 1+i, \lambda_2 = 2 (1-i), \lambda_3 = 3 (1+i), \alpha _1 = 0.1, \alpha _2 = 0.2, \alpha _3 = 0.3, \beta_1 = \beta_2 = \beta_3 = 1 $; Right panel is the corresponding density plot.

    In this paper, the nonlocal DNLS Eq (1.2) has been analytically studied. Firstly, using the Lax pair of the coupled Eq (2.1), from which the reduction conditions lead to Eq (1.2), we have constructed arbitrary order DTs in a more streamlined manner. From zero and non-zero seed solutions, new Wronskian-type determinant solutions are obtained. Specifically, we have obtained new solutions by applying the first four orders DT.

    Starting from zero seeds, due to the nonlocality of the equation, odd-order DTs will cause the background of the solutions to diverge towards infinity. For even-order DTs, the background of the solutions will not go to infinity unless the square of eigenvalues $ \lambda^2 $ are pure imaginary, in order to maintain the reduction conditions, which could increase the difficulty in selecting parameter values. Soliton solutions without singularities have been obtained for specific parameter values, as demonstrated in Figures 3, 7, and 9. These new solutions are all periodic and bounded, similar to the results reported in [9]. Besides, when one eigenvalue tends to another one, generalized DT can be constructed. Taking the solitons in Figure 7 as an example, we can obtain new solutions which are mixed-type of exponential and rational functions with $ \lambda_2 = \lambda_1 $, which can be seen Figure 8. Although the solution in Figure 7 is bounded with $ \lambda_2 \neq \lambda_1 $, there are two singularities, causing the solitons to blow up to infinity.

    Starting from non-zero seeds, we have obtained various solutions including the periodic solutions and rogue waves. If the eigenvalues are real or pure imaginary numbers, there will be constraints on the parameters. However, these solutions inherently possess singularities. Nevertheless, we have constructed soliton solutions for the first few orders. Figure 1 displays the periodic one-soliton, which degrades into a rogue wave (see Figure 2) when the magnitude of the eigenvalue is identical to the amplitude of the seed solution. Similarly, periodic two- and three-soliton solutions can also degrade or partially degrade into rogue waves, which can be observed in Figures 5, 6(c), and 6(d). When the eigenvalues are taken as complex numbers, the interaction of two solitons has been shown in Figure 4. Figure 6(a) shows a superposition and interaction of Figures 1(a) and 4. When the real eigenvalue equals to $ \pm \rho $, the periodic soliton will disappear, as shown in Figure 6(b).

    In addition, the value of $ \varepsilon $ does not affect much except the location of the singularities, which is different from the nonlocal NLS Eq (1.1). We hope that the work presented in this paper can provide a valuable reference and assistance for the study of nonlocal integrable systems.

    The author declares he has not used Artificial Intelligence (AI) tools in the creation of this article.

    Thanks to the valuable suggestions of the editor and reviewers. Work of this paper was supported by State Key Laboratory of Heavy Oil Processing (SKLHOP2024115808).

    The author declares no conflict of interest.

    [1] Abubakar A., Li M., Pan G., Liu J., Habashy T.M. (2011) Joint MT and CSEM data inversion using a multiplicative cost function approach. Geophysics 76: F203-F214. doi: 10.1190/1.3560898
    [2] Colombo D., De Stefano (2007) M., Geophysical modeling via simultaneous joint inversion of seismic, gravity, and electromagnetic data. The Leading Edge 26: 326-331. doi: 10.1190/1.2715057
    [3] Colombo D., Mantovani M., DeStefano M., Garrad D., Al Lawati H. (2007) Simultaneous Joint Inversion of Seismic and Gravity data for long offset Pre-Stack Depth Migration in Northern Oman, CSEG, Calgary.
    [4] Commer M., Newman G.A. (2009) Three-dimensional controlled-source electromagnetic andmagnetotelluric joint inversion. Geophys. J. Int 178: 1305-1316. doi: 10.1111/j.1365-246X.2009.04216.x
    [5] Constable S., Srnka L. (2007) An introduction to marine controlled-source electromagnetic methods for hydrocarbon exploration. Geophysics 72: WA3-WA12. doi: 10.1190/1.2432483
    [6] Dell’Aversana P., Zanoletti F. (2010) Spectral analysis of marine CSEM data symmetry. First Break 28: 44-51.
    [7] Dell’Aversana P., Bernasconi G., Miotti F., Rovetta D. (2011) Joint inversion of rock properties from sonic, resistivity and density well-log measurements. Geophysical Prospecting 59: 1144-1154. doi: 10.1111/j.1365-2478.2011.00996.x
    [8] Dell’Aversana P., Colombo S., Ciurlo B., Leutscher J., Seldal J. (2012) CSEM data interpretation constrained by seismic and gravity data. An application in a complex geological setting. First Break 30: 35-44.
    [9] Dell’Aversana P. (2014) Integrated Geophysical Models: Combining Rock Physics with Seismic, Electromagnetic and Gravity Data. EAGE Publications .
    [10] DeStefano M., Golfré Andreasi F., Re S., Virgilio M., Snyder F.F. (2011) Multiple-domain, simultaneous joint inversion of geophysical data with application to subsalt imaging. Geophysics 76: R69. doi: 10.1190/1.3554652
    [11] Eidesmo T., Ellingsrud S., MacGregor L.M., Constable S., Sinha M.C., Johansen S., Kong F.N., Westerdah H. (2002) Sea bed logging, a new method for remote and direct identification of hydrocarbon filled layers in deepwater areas. First Break 20: 144-152.
    [12] Gallardo L.A., Meju M.A. (2003) Characterization of heterogeneous near-surface materials by joint 2D inversion of dc resistivity and seismic data. GEOPHYSICAL RESEARCH LETTERS 30: 1658. doi: 10.1029/2003GL017370
    [13] Gallardo L.A., Meju M.A. (2004) Joint two-dimensional DC resistivity and seismic travel time inversion with cross-gradients constraints. J. geophys 109.
    [14] Gallardo L.A., Meju M.A. (2007) Joint two-dimensional cross-gradient imaging of magnetotelluric and seismic traveltime data for structural and lithological classification. Geophys. J. Int. 169: 1261-1272. doi: 10.1111/j.1365-246X.2007.03366.x
    [15] Haber E., Oldenburg D.W (1997) Joint inversion: a structural approach. Inverse Problems 13: 63-77. doi: 10.1088/0266-5611/13/1/006
    [16] Hu W., Abubakar A., Habashy T.M. (2009) Joint electromagnetic and seismic inversion using structural constraints. Geophysics 74: R99-R109. doi: 10.1190/1.3246586
    [17] Jin J. (2002) The Finite Element Method in Electromagnetics. John Wiley&Sons .
    [18] Kennett B.L.N. (1983) Seismic wave propagation in stratified media. Cambridge University Press .
    [19] Liang L., Abubakar A., Habashy T.M. (2011) Estimating petrophysical parameters and average mud-filtrate invasion rates using joint inversion of induction logging and pressure transient data. Geophysics 76: E21-E34. doi: 10.1190/1.3541963
    [20] Moorkamp M., Heincke B., Jegen M., Roberts A.W., Hobbs R.W. (2011) A framework for 3-D joint inversion of MT, gravity and seismic refraction data. Geophys. J. Int 184: 477-493. doi: 10.1111/j.1365-246X.2010.04856.x
    [21] Raymer L.L., Hunt E.R., Gardner J.S. (1980) An improved sonic transit time to porosity transform. 21st Annual Logging Symposium. Transactions of the Society of Professional Well Log Analysts P546.
    [22] Schön J.H. (2011) Physical Properties of Rocks: Fundamentals and Principles of Petrophysics. Elsevier .
    [23] Tarantola A. (2005) Inverse Problem Theory and Methods for Model Parameter Estimation. Society for Industrial and Applied Mathematics .
    [24] Thomson W.T. (1950) Transmission of Elastic Waves through a Stratified Solid medium. Jour. Appl. Phys. 21: 89-93. doi: 10.1063/1.1699629
    [25] Vozoff K., Jupp D.L.B. (1975) Joint Inversion of Geophysical Data. Geophys. J 42: 977-991. doi: 10.1111/j.1365-246X.1975.tb06462.x
  • Reader Comments
  • © 2016 the Author(s), licensee AIMS Press. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0)
通讯作者: 陈斌, bchen63@163.com
  • 1. 

    沈阳化工大学材料科学与工程学院 沈阳 110142

  1. 本站搜索
  2. 百度学术搜索
  3. 万方数据库搜索
  4. CNKI搜索

Metrics

Article views(15227) PDF downloads(9306) Cited by(9)

Figures and Tables

Figures(19)  /  Tables(4)

/

DownLoad:  Full-Size Img  PowerPoint
Return
Return

Catalog