Search

This paper presents a multistep approach for the rehabilitation of the deteriorated and intermittently operated water distribution network (WDN) proposed by the organizers of the joint WDSA CCWI 2022 Conference as the case study for the battle. In the rehabilitation, various interventions are considered with the final objective to improve the operation of the WDN in terms of hours of service to users and total volume supplied to meet their demands, including pipe and device (pump/valve) replacements, leak repairs, and extended period optimization of device settings. The multistep approach is proposed to tame the extremely large space of decision variables and includes the following steps: (1) subdivision of the WDN into main chain and district metered areas (DMAs), rehabilitation of (2) the main chain and (3) the DMAs while looking at the final year of the rehabilitation, (4) sequencing of the interventions, and (5) optimization of device settings. Compared to other methodologies in the literature, the main novelty and merit of the present approach consist of the way the rehabilitation interventions are selected, i.e., by using engineering judgment and by maximizing the flow capacity of the main chain and the global resilience–failure index in the DMAs. [ABSTRACT FROM AUTHOR]

A new two-step method is introduced in the present paper. The new algorithm is conditionally P-Stable and an economical scheme. It has vanished phase-lag and it's first to fourth derivatives. We use for the new scheme the symbol LOWPF5DECN2ST. We apply the newly introduced method to problems in Quantum Chemistry. The new scheme is defined as economical since it uses 4 function evaluations per step in order to achieve an algebraic order (AOR) of 10. [ABSTRACT FROM AUTHOR]

A new two-step method, for the numerical solution of problems in quantum chemistry, is introduced in the present paper. The new algorithm is conditionally P-Stable and an economical scheme. It has vanished phase–lag and it's first to fourth derivatives. We use for the new scheme the symbol LOWPF4DECN2ST. We apply the newly introduced method to problems in Quantum Chemistry. The new scheme is defined as economical since it uses 4 function evaluations per step in order to achieve an algebraic order (AOR) of 10. [ABSTRACT FROM AUTHOR]

A new two-step algorithm is developed in this paper. The new method is singularly P-Stable and is an economic scheme. It has vanished phase-lag and its derivatives up to order three. We use the symbol LOWPF3DECN2ST in order to present the new algorithm. We apply the new developed algorithm to problems in Chemistry. It is an economic method since it uses 4 function evaluations per step in order to achieve an algebraic order 10. [ABSTRACT FROM AUTHOR]

During transient process, it may take plenty of steps for PMSM to reach the reference torque and flux linkage. Multistep model predictive torque and flux control (MPTC) can select the best sequence of voltage vectors from the initial state to the reference state to achieve the fastest torque response. However, the computation burden is a significant challenge for real-time implementation. This paper proposes a novel fast-response MPTC strategy for PMSM drives. The reference torque is converted to flux linkage in d-axis and q-axis to eliminate the weighting factor in cost function. During the transient process, Pontryagin's maximum principle is used to design minimum-time flux linkage trajectories from the initial state to the reference state. In each control period, along the reference flux linkage trajectories, one-step MPTC is used to select the best voltage vector. The computational burden and dynamic performance of the proposed method are verified by experiments. [ABSTRACT FROM AUTHOR]

In the present paper, we introduce a new two-step scheme which is singularly P-Stable and which belongs to the economic methods. The new scheme has zero phase–lag and its derivatives up to order two. The new algorithm is symbolized as LOWPF2DECN2ST. The new scheme is applied to problems in Quantum Chemistry. The new scheme belongs to the economic methods since it achieves an algebraic order 10 using 4 function evaluations per step. [ABSTRACT FROM AUTHOR]

A new phase-fitting singularly P-Stable economical two–step method (which is symbolized as PHAFITECON2STEP) is produced in this paper. The newly introduced method has eliminated phase-lag and its derivatives up to order seven and can be applied to initial or boundary value problems with oscillating and/or periodical solutions. The new method is applied to problems in Quantum Chemistry. We call the newly produced method economical since to achieve the highest possible algebraic order, uses the minimum number of function evaluations per step. [ABSTRACT FROM AUTHOR]

A new singularly P-Stable two-step algorithm of economical type with zero phase–lag and its derivative is produced in this paper. We symbolized the new scheme as LOWPFTECON2STEP. We apply the new algorithm to problems in Chemistry. The new algorithm achieves a 10th algebraic order using four function evaluations per step. For this reason, is called economical. [ABSTRACT FROM AUTHOR]

One of the main objectives for people with intellectual disability (with or without other disabilities) is the ability to perform multistep activities (e.g. preparing a sandwich) without external help from a caregiver. This paper provides a review of studies that evaluated technology systems to teach or support people with intellectual and other disabilities to carry out multistep functional activities through the presentation of single-step instructions. A literature search was performed for English language articles indexed in PubMed, PsycINFO and Web of Science. A narrative synthesis of the articles selected was provided together with a quantitative estimate of the effectiveness of their technology-aided interventions. The latter was carried out via the Percent of Nonoverlapping Data (PND) method. Twenty-six articles met inclusion criteria, with most studies following a single-subject research design (n = 25). The technologies identified were grouped into three categories (self-operated, automatic, and intelligent). Overall, the results are encouraging in that most of the technology solutions reviewed led to positive outcomes in terms of increasing independence of people with intellectual disability in performing relevant multistep activities (average PND score = 96.3%). This review highlights that technology systems designed to present single-step instructions can be effective in teaching or supporting the independent performance of multistep activities by people with intellectual disability with or without other disabilities. Only minimal research exists on development and use of intelligent systems. [ABSTRACT FROM AUTHOR]

A four stages twelfth algebraic order symmetric two-step method with vanished phase-lag and its first and second derivative is developed in this paper for the first time in the literature. More specifically in this paper the following will be investigated: (i) the phase-lag analysis for the development of the new method, (ii) the construction of the new method, (iii) the local truncation error analysis which is based on the radial Schrödinger equation, (iv) the interval of periodicity analysis and the stability analysis which is based on a scalar test equation with frequency not equal with the frequency of the scalar test equation used for the phase-lag analysis, (v) the error estimation procedure based on the algebraic order, (vi) the numerical results from our numerical tests for the study of the efficiency of the new obtained method. The numerical tests are based on the numerical solution of the Schrödinger equation. [ABSTRACT FROM AUTHOR]

In this paper a four stages symmetric two-step method with vanished phase-lag and its first derivative with high algebraic order is developed for the first time in the literature. More pricesly in this paper the following are presented: (1) the phase-lag analysis for the construction of the new high algebraic order method, (2) the construction of the new method, (3) the error analysis based on the radial Schrödinger equation, (4) the interval of periodicity analysis and the stability analysis, (5) a new error estimation procedure based on the phase-lag (6) the numerical tests for the study of the efficiency of the new obtained method which are based on the numerical solution of the Schrödinger equation. [ABSTRACT FROM AUTHOR]

A two stage symmetric two-step method with vanished phase-lag and its first, second, third and fourth derivatives with low computational cost is developed in this paper for the first time in the literature. More specifically in this paper we present: [ABSTRACT FROM AUTHOR]

A new ECONO2STEP (economical two-step) method with eliminated phase-lag and its derivatives up to order six is developed in this paper. The newly developed method can be applied to initial or boundary value problems with oscillating and/or periodical solutions. We applied the new method to problems in Quantum Chemistry. The newly introduced method is called economical since using the minimum number of function evaluations per step achieves the highest possible algebraic order. [ABSTRACT FROM AUTHOR]

A new ECON2STEP (Economical Two-Step Method) method with vanished phase-lag and its derivatives up to order five is introduced in this paper, for initial or boundary value problems with solutions of oscillating and/or periodical behavior, with an application on problems in Chemistry. [ABSTRACT FROM AUTHOR]

A study on the vanishing of the phase-lag and its first and second derivatives for a family of explicit four-step methods first introduced by Anastassi and Simos (J Comput Appl Math 236:3880-3889, ) is presented in this paper. The methods investigated in this paper belongs to the category of methods with frequency dependent coefficients. For these methods we will investigate the procedure of vanishing of the phase-lag and its first and second derivatives. For the new proposed methods we will define the local truncation error and we will study an local truncation error analysis. Finally we will compare the results of the error analysis with other known methods of the literature. We will study also the stability analysis of the new proposed method. We will apply the new produced methods on the resonance problem of the Schrödinger equation in order to investigate their efficiency. [ABSTRACT FROM AUTHOR]

A new finite difference pair is produced in this paper, for the first time in the literature. The characteristics of the new finite diffence pair are: (1) is of symmetric two-step, (2) is four-stages, (3) is of tenth-algebraic order, (4) the production of the pair is based on the following approximations for the layers: first and second layer are approximated on the point $$x_{n-1}$$ , third layer is approximated on the point $$x_{n}$$ and finally fourth layer is approximated on the point $$x_{n+1}$$ , (5) has vanished the phase-lag and its first and second derivatives, (6) has excellent stability properties for all type of problems, (7) has an interval of periodicity equal to $$\left( 0, \infty \right) $$ . We present for the new obtained finite difference pair a full theoretical analysis. The effectiveness of the new developed finite difference pair is proved by its application on systems of coupled differential equations arising from the Schrödinger equation. [ABSTRACT FROM AUTHOR]

In this paper we develop a new ECO2STEP (Economical Two-Step Method) method with phase-lag and its derivatives up to order four equal to zero, for initial or boundary value problems with oscillating and/or periodical solutions with an application on problems in Quantum Chemistry. We call the new introduced method economical since it has achieved the highest possible algebraic order using the minimum number of function evaluations per step. [ABSTRACT FROM AUTHOR]

A new FINDIFF (Finite Difference) method with zeroing phase-lag and its derivatives up to order two, for initial or boundary value problems with periodical and/or oscillating solutions with an application on problems in Quantum Chemistry, is proposed in this paper. The method is considered to belong to the economical class of methods since it is of the highest possible algebraic order using the minimum number of function evaluations per step. [ABSTRACT FROM AUTHOR]

A new ECOFINDIFF (economical finite difference method) with vanished phase-lag and its derivatives up to order three, for oscillating and/or periodical initial or boundary value problems with an application on problems in Chemistry, is developed in this paper. The proposed method is called economical since it has achieved the highest possible algebraic order using the minimum number of function evaluations per step. [ABSTRACT FROM AUTHOR]

A new EcoFinDif (Economical Finite Difference) method with eliminated phase-lag and its first derivative, for periodical and/or oscillating initial or boundary value problems with an application on problems in Chemistry is presented in this paper. The method is considered economical since it is of fourteenth algebraic order and uses the minimum number of function evaluations per step. [ABSTRACT FROM AUTHOR]

In this paper we will develop an explicit fourth algebraic order four-step method with phase-lag and its first and second derivatives vanished. The comparative error and the stability analysis of the above mentioned paper is also presented. The new obtained method is applied on the resonance problem of the Schrödinger equationIn order in order to examine its efficiency. The theoretical and the computational results shown that the new obtained method is more efficient than other well known methods for the numerical solution of the Schrödinger equation and related initial-value or boundary-value problems with periodic and/or oscillating solutions. [ABSTRACT FROM AUTHOR]

A new FiDif (finite difference) method with zeroing phase-lag and its derivatives up to order seven, for initial or boundary value problems with periodical and/or oscillating solutions for problems in Quantum Chemistry is developed in this paper. [ABSTRACT FROM AUTHOR]

A new Finite Difference complete in phase method with vanished derivatives of the Phase-lag up to order five for the initial value problems with periodical and/or oscillating solutions is produced in the present paper. [ABSTRACT FROM AUTHOR]

In the present paper we introduce a new FD (Finite Difference) method with eliminated phase–lag and its derivatives up to order six, with also optimal stability properties, for periodic initial or boundary value problems in Chemistry. [ABSTRACT FROM AUTHOR]

In this paper we introduce a new finite difference phase-fitted method with eliminated derivatives of the phase-lag up to order four for periodic initial value problems. [ABSTRACT FROM AUTHOR]

In this paper we introduce, for the first time in the literature, a three-stages two-step method. The new algorithm has the following characteristics: (1) it is a two-step algorithm, (2) it is a symmetric method, (3) it is an eight-algebraic order method (i.e of high algebraic order), (4) it is a three-stages method, (5) the approximation of its first layer is done on the point $$x_{n-1}$$ and not on the usual point $$x_{n}$$ , (6) it has eliminated the phase-lag and its derivatives up to order two, (7) it has good stability properties (i.e. interval of periodicity equal to $$\left( 0, 22 \right) $$ . For this method we present a detailed analysis : development, errorand stability analysis. The new proposed algorithm is applied to systems of differential equations of the Schrödinger type in order to examine its efficiency. [ABSTRACT FROM AUTHOR]

In this paper, we will develop a four-stage high algebraic order symmetric two-step method with vanished phase-lag and its first up to the fourth derivative. For the proposed method, we will study the following: the phase-lag analysis of the new method; the development of the new method; the local truncation error analysis which is based on the radial Schrödinger equation; the stability and the interval of periodicity analysis which is based on a scalar test equation with frequency different than the frequency of the scalar test equation used for the phase-lag analysis; the error estimation procedure which is based on the algebraic order; and the numerical results from our numerical tests for the examination of the efficiency of the new obtained method. The numerical tests are based on the numerical solution of the Schrödinger equation. [ABSTRACT FROM AUTHOR]

A hybrid tenth algebraic order two-step method with vanished phase-lag and its first, second, third, fourth and fifth derivatives are obtained in this paper. We will investigate It will be proved that the developed method is effective for the approximate solution of the Schrödinger equation and related periodical or oscillatory initial value or boundary value problems. [ABSTRACT FROM AUTHOR]

In this paper and for the first time in this scientific discipline, we introduce a new multi-stage two-step teeming in phase algorithm with meliorated characteristics. A theoretical, computational and numerical consideration is also presented. The sufficiency of the new computational algorithm is tried on using systems of coupled differential equations which represent computational problem in quantum chemistry. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a new four-stages two-step fraught in phase method for the first time in this area. A complete theoretical study is presented, and the capability of the new method is sampled using systems of coupled differential equations which represent quantum chemistry problems. [ABSTRACT FROM AUTHOR]

Summary: This paper presents a framework for incorporating arbitrary implicit multistep schemes into the lattice Boltzmann method. While the temporal discretization of the lattice Boltzmann equation is usually derived using a second‐order trapezoidal rule, it appears natural to augment the time discretization by using multistep methods. The effect of incorporating multistep methods into the lattice Boltzmann method is studied in terms of accuracy and stability. Numerical tests for the third‐order accurate Adams‐Moulton method and the second‐order backward differentiation formula show that the temporal order of the method can be increased when the stability properties of multistep methods are considered in accordance with the second Dahlquist barrier. A general multistep time integration framework for the lattice Boltzmann method (LBM) is presented. Concretely, a third‐order Adams‐Molton LBM and a second‐order backward differentiation formula LBM are developed and investigated concerning stability, accuracy, and applicability in comparison to the standard trapezoidal rule. It is shown that the order of convergence can be increased by high‐order multistep methods, taking a changed stability region into account. [ABSTRACT FROM AUTHOR]

In this paper and for the first time in this research area we formulate a new multistage multistep full in phase method with meliorated properties. A theoretical, computational and numerical contemplation is also presented. The sufficiency of the new scheme is tried on using systems of coupled differential equations which represent quantum chemistry problems. [ABSTRACT FROM AUTHOR]

In this paper and for the first time in this research discipline we form a new multistage multistep complete in phase method with meliorated properties. A theoretical, computational and numerical contemplation is also presented. The sufficiency of the new scheme is tried on using systems of coupled differential equations which represent quantum chemistry problems. [ABSTRACT FROM AUTHOR]

In this paper and for the first time in this research discipline we form a new multistage multistep complete in phase method with meliorated properties. A theoretical, computational and numerical contemplation is also presented. The sufficiency of the new scheme is tried on using systems of coupled differential equations which represent quantum chemistry problems. [ABSTRACT FROM AUTHOR]

A new four stages two-step in phase algorithm with best possible characteristics is formed, for the first time in the bibliography, in this paper. We represent a theoretical and numerical study. The adequacy of the new method is tried out using systems of coupled differential equations. [ABSTRACT FROM AUTHOR]

In the present paper and for the first time in the bibliography, we form a new multiple stages multistep complete in phase algorithm with meliorated properties. A detailed theoretical and computational study is also represented. The competence of the new algorithm is tested using systems of coupled differential equations of the Schrödinger type. [ABSTRACT FROM AUTHOR]

In this paper we introduce, for the first time in the literature, an optimized multistage symmetric two-step method. This method is considered as optimized due to the following reasons: (1) it is of tenth-algebraic order scheme, (2) it has obliterated the phase-lag and its first, second, third and fourth derivatives, (3) it has improved stability characteristics, (4) it is a P-stable method. For the new proposed multistage symmetric two-step method we present a full theoretical investigation consisted of: (1) local truncation error and comparative error analysis, (2) stability analysis and (3) interval of periodicity analysis. The effectiveness of the new builded multistage symmetric two-step method is evaluated on the solution of systems of coupled differential equations of the Schrödinger type. [ABSTRACT FROM AUTHOR]