Dual Scheme Research Articles

World Englishes and L2 pedagogy: Focus on Error Corrections

This paper hopes to identify learning difficulties of students coming from a different variety of World Englishes (WE) in learning English as a second language (ESL) focusing on Hindi English. It examines the implications of Hindi English as a WE variety on language learning and teaching. An analysis of Hindi English (HE) in English language learning is provided to help understanding of multilingual realities of communication towards a contextualization of teaching conventions. For example, what is the stance an ESL instructor might assume while dealing with influences of native language in the English language classroom? How tolerant should instructors be in recognizing “error” in L2 learning? Should ESL teachers adhere to academic rules and conventions from other settings or embrace diverse accents and language needs of ESL students? Finally, the paper proposes a dual scheme of “error correction” and “accommodation” to the way English is taught to students in the outer and expanding circles of English. Following discussions that focus on features of spoken and written English that call for a different treatment of the language skills, and considering L1 interference in L2 learning, the paper suggests that “errors” in Writing need be corrected while “mistakes” in Speaking may be “accommodated”.

A RANDOMIZED CARRIER-BASED DISCONTINUOUS PULSE WIDTH MODULATION STRATEGY FOR NEUTRAL POINT CLAMPED THREE-LEVEL INVERTER

This article introduces a novel approach called randomized carrier-based discontinuous pulse width modulation (RCDPWM) to address the challenge of mitigating both low-order and high-order harmonics concentrated at the switching frequency and its integer multiples in the output voltage and current of a three-level inverter. The proposed strategy reduces switching losses and a wide dispersion of voltage and current harmonics with significantly smaller amplitudes by integrating features from discontinuous and randomized PWM methods. This characteristic proves beneficial for enhancing efficiency and electromagnetic compatibility. The RCDPWM strategy involves three schemes: two simple schemes (one random parameter), randomized pulse position modulation (RPP-DPWM) and randomized carrier frequency modulation (RCF-DPWM), and a dual scheme combining the two previous ones (RPPRCF-DPWM). Power spectral density (PSD) is used to assess the effectiveness of the proposed strategy in quantitatively analyzing the harmonic dispersion degree. The results demonstrate that the proposed RCDPWM strategy significantly expands harmonic clusters around the switching frequency, reducing its intensity. The spectrum analysis revealed that the RPPRCF-DPWM scheme is the most effective in spreading the output voltage and current spectrum compared to simple schemes (RPP-DPWM and RCF-DPWM).

National And Public Interest Perspective on the Governance and Regulation of Carbon Capture and Storage Implementation in Indonesia

Recently Indonesian Government issued two important regulations regarding Carbon Capture Storage (CCS) namely, President Regulation No. 14/2024 and Ministry of Energy and Mineral Resources Regulations No. 2/2003. Both regulations have caused Indonesia's CCS Legal and Regulatory score by the Global CCS Institute to increase significantly. There are three criteria applied by the Global CCS Institute to define the score: regulation of trans boundaries movement of CCS, specific legal and regulatory framework, and facilitation of early project. Despite the increase in CCS score, some essential questions remain as crucial problems that are not solvable easily. Those questions regarding the national and common interest of Indonesian people by the issuance of both legal and regulations are still unclear, at least from the common people's perspective. The Presidential Regulation define dual schemes for CCS implementation: Contract Scheme and Permit Scheme. From the common people's perspective, both schemes need to be exercised further to respond to the public questions properly. Therefore, any reason behind the implementation of those two schemes as well as any potential benefit for Indonesia by implementing those two schemes in parallel are very important to be reviewed and analyzed. Reinforcement of Oil and Gas Production Sharing Contract Principles in the implementation of CCS in Indonesia are more favourable for the National and Public Interest Perspective.

Decentralized H2 Control for Discrete-Time Networked Systems With Positivity Constraint.

In this brief, we study the decentralized H2 state-feedback control problem for networked discrete-time systems with positivity constraint. This problem (for a single positive system), raised recently in the area of positive systems theory, is known to be challenging due to its inherent nonconvexity. In contrast to most works, which only provide sufficient synthesis conditions for a single positive system, we study this problem within a primal-dual scheme, in which necessary and sufficient synthesis conditions are proposed for networked positive systems. Based on the equivalent conditions, we develop a primal-dual iterative algorithm for solution, which helps prevent from converging to a local minimum. In the simulation, two illustrative examples are employed for verification of our proposed results.

Performance evaluation of regulatory schemes for retired electric vehicle battery recycling within dual-recycle channels

As electric vehicles (EVs) are developing at a rapid pace, the foreseeable “scrap tide” of EV batteries poses a severe challenge to ecological protection. This article investigates a dual-recycle channel closed-loop supply chain and provides regulatory solutions to retired EV batteries' recycling. Specifically, we construct four supervision scenarios: S1 no policy intervention, S2 reward-penalty scheme, S3 deposit-refund scheme, and S4 dual scheme combining S2 and S3. Based on the Stackelberg game and empirical data, all scenarios' recycling performance is evaluated and compared with a view to “society, economy, and environment”. The results revealed: (1) Compared with S1, the recycling rate and carbon reduction rate in S2∼S4 increase by 2.6049%/0.0092%, 4.0379%/0.0285%, and 6.6660%/0.0379%, respectively; (2) The difference between S2 and S3 in recycling performance depends on regulatory intensities, yet the latter places greater burdens on consumers and firms. The S4 presents optimal environmental performance but at the expense of socioeconomic development; (3) As regulatory intensity increases, social welfare rises driven by environmental benefits, then falls due to overburdened supply chain profits, consumer surplus, and policy expenditures; (4) Carbon trading prices and EVs' potential market sizes affect regulatory schemes’ operations. Our results contribute to policy-making and managerial practices for EV battery recycling.

SpectralMAP: Approximating Data Manifold With Spectral Decomposition

Dimensionality reduction is widely used to visualize complex high-dimensional data. This study presents a novel method for effective data visualization. Previous methods depend on local distance measurements for data manifold approximation. This leads to unreliable results when a data manifold locally oscillates because of some undesirable effects, such as noise effects. In this study, we overcome this limitation by introducing a dual approximation of a data manifold. We roughly approximate a data manifold with a neighborhood graph and prune it with a global filter. This dual scheme results in local oscillation robustness and yields effective visualization with explicit global preservation. We consider a global filter based on principal component analysis frameworks and derive it with the spectral information of the original high-dimensional data. Finally, we experiment with multiple datasets to verify our method, compare its performance to that of state-of-the-art methods, and confirm the effectiveness of our novelty and results.

Energy-Efficient Mobile Edge Computing Under Delay Constraints

Green communication is one of the key goals of the beyond 5G networks. However, as more and more delay sensitive applications emerge, the contradiction between task delay requirement and energy conservation becomes more and more prominent on the device side. This paper focuses on a mobile edge computing system where local computing capability and edge computing capability are both limited, which may lead to task discarding due to delay violation. An energy consumption minimization problem is first formulated under the binary offloading and the partial offloading modes. Then a low-complexity heuristic scheme and a Lagrange dual scheme are proposed to jointly optimize the task scheduling and resource allocation under those two modes respectively. Particularly, a task processing priority model is designed to effectively reduce the number of discarded tasks and improve the service performance of the MEC server. The effectiveness of the proposed schemes is validated by extensive simulations with comparison to other baseline schemes.

Operationalising Vergnaud’s Notion of Scheme in Task Design in Online Learning Environments to Support the Implementation of Formative Assessment

Abstract This paper presents an implementation process model for designing and implementing tasks that provide formative feedback in the online learning environment of mathematics classrooms. Specifically, the model operationalises components of Vergnaud’s notion of scheme. The implementation process model features a task sequence guided by controlled variation and a ‘dual scheme idea’. Using such a sequence of tasks, this work illustrates how Vergnaud’s notion of scheme can be used to aid teachers in hypothesising about their learners’ understanding of problems involving linear equations, ultimately providing improved feedback for teachers and improved opportunities for student learning in online environments. In Denmark, the online environment matematikfessor.dk is used by approximately 80% of Danish K-9 students. The impact sheet to this article can be accessed at 10.6084/m9.figshare.19493846.

A 1 V 10-bit highly linear and monotonic digital-to-time converter with 0.066-LSB DNL utilizing a glitch-free dual reset method and switchable supply regulation scheme

A 1 V 10-bit highly linear and monotonic digital-to-time converter with 0.066-LSB DNL utilizing a glitch-free dual reset method and switchable supply regulation scheme

Analysis of output voltage ripple for dual randomized PWM buck converter operating in continuous and discontinuous conduction modes

Dual Randomized Pulse Width Modulation (DRPWM) is renowned for its better effectiveness than Simple Randomized Pulse Width Modulation (SRPWM) in reducing conducted Electro-Magnetic Interferences (EMI) in power converters. However, the introduction of low-frequency ripples into the output voltage by dual randomization has not yet been addressed; this effect is investigated in this paper for a buck converter operating in both the continuous conduction mode (CCM) and the discontinuous conduction mode (DCM). First, the modulating principle is presented. Then, a general analytical expression for power spectral density (PSD) of the input current is derived and validated for the proposed DRPWM scheme for both the CCM and DCM. A comparison of the PSDs of the input current for all RPWM schemes in both the CCM and DCM shows the PSD spreading effectiveness of the dual scheme as compared to simple schemes. Finally, the low-frequency output ripple is analysed using the PSD of output voltage. The results reveal that the output voltage ripple is affected by all the randomized schemes in both the CCM and the DCM. Also, the dual scheme (RCFM-RPPM) introduces the highest low-frequency voltage ripple, especially in the CCM and for low duty cycles. In DCM, the RPPM scheme gives the lowest voltage ripple, while the RCFM scheme gives the lowest voltage ripple in the CCM. The results are confirmed by both theory and simulations.

Correction to: A dual layer security scheme for medical images using Hessenberg and singular value decompositions

Correction to: A dual layer security scheme for medical images using Hessenberg and singular value decompositions

The two modern liberties of Constant and Berlin

ABSTRACT The paper challenges the general perception that the positive–negative freedom discourse privileges negative liberty. It demonstrates that Constant and Berlin’s dual freedom conceptual scheme contains the blueprint of a modern concept of positive freedom and it reveals the nature of negative freedom in an entirely new light. Constant’s ancient and modern liberties have many similarities with Berlin’s two concepts of freedom – positive and negative. The paper shows that these similarities warrant a parallel study and allow us to examine the relation between the two sides of the freedom dichotomy by using the compound terms modern/negative and ancient/positive freedom. It is argued that understanding the relation between the two freedoms depends on accepting ancient/positive liberty as practiced by the participants of modern revolutions. Then we can see why this freedom can both violate and complement modern/negative freedom. The paper argues that the combined tension and mutual dependency of the two freedoms can be explained by tapping into a metaphysical study of human agency, where metaphysics is understood as conceptualisation of moral experience. This helps demonstrate why Constant’s modern liberty and Berlin’s negative liberty rely on satisfaction as a key category reflecting individuals’ capacity for subjective judgement.

Effectiveness and Safety Analysis of PIs/r Based Dual Therapy in Treatment-Naïve, HIV/AIDS Patients: A Network Meta Analysis of Randomized Controlled Trials.

Background: Dual anti-retroviral therapy is the main proven valuable intervention type for treating naïve HIV/AIDS. Currently, no high-quality evidence is available regarding the best dual schemes. Objectives: The aim of this study is to evaluate the effectiveness and safety of PIs/r-based dual therapy in treatment-naïve HIV/AIDS patients by using network meta-analysis. Methods: Randomized controlled trials of PIs/r-based dual therapy in treatment-naïve HIV/AIDS were searched based on Embase, PubMed and Cochrane library database from January 2006 to June 2021. Taking viral suppression rate, CD4+T cell count changes from baseline as the primary indicator and adverse events rate as secondary indicator, the network meta-analysis was performed on Review Manager and STATA software. Heterogeneity was assessed by the Q statistic and I2. We registered our protocol in Prospero with ID CRD42021275466. Results: Among 15 randomized controlled trials (3,497 patients and 7 PIs/r-based dual therapy) were reviewed in this study. According to the forest map, DRV/r + INSTIs was more effective compared to triple therapy (TT) in viral suppression [OR 0.82, 95% CI (0.61–1.11)], in CD4+T cell count changes from baseline [MD 1.9, 95% CI (0.7, 3.1), I 2 86%], in adverse events [OR 0.98, 95% CI (0.68–1.39)]. Furthermore, SUCRA ranking analysis indicated that DRV/r + INSTIs was superior to TT in viral suppression (DRV/r + INSTIs 75.5% > TT 41.2%) and in immune construction (DRV/r + INSTIs 67% > TT 42%). In addition, DRV/r + INSTIs was similar to TT in adverse events (DRV/r + INSTIs 54.9% ≈ TT 54.7%). Conclusion: DRV/r + INSTIs was obviously superior to TT in viral suppression and immune reconstruction, and was not higher than TT in adverse events. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42021275466

Blockchain Based Image Encryption with Spiral Mapping and Hashing Techniques in Dual Level Security Scheme

Blockchain Based Image Encryption with Spiral Mapping and Hashing Techniques in Dual Level Security Scheme

Optimal Dual Schemes for Adaptive Grid Based Hexmeshing

Hexahedral meshes are a ubiquitous domain for the numerical resolution of partial differential equations. Computing a pure hexahedral mesh from an adaptively refined grid is a prominent approach to automatic hexmeshing, and requires the ability to restore the all hex property around the hanging nodes that arise at the interface between cells having different size. The most advanced tools to accomplish this task are based on mesh dualization. These approaches use topological schemes to regularize the valence of inner vertices and edges, such that dualizing the grid yields a pure hexahedral mesh. In this article, we study in detail the dual approach, and propose four main contributions to it: (i) We enumerate all the possible transitions that dual methods must be able to handle, showing that prior schemes do not natively cover all of them; (ii) We show that schemes are internally asymmetric, therefore not only their construction is ambiguous, but different implementative choices lead to hexahedral meshes with different singular structure; (iii) We explore the combinatorial space of dual schemes, selecting the minimum set that covers all the possible configurations and also yields the simplest singular structure in the output hexmesh; (iv) We enlarge the class of adaptive grids that can be transformed into pure hexahedral meshes, relaxing one of the tight topological requirements imposed by previous approaches. Our extensive experiments show that our transition schemes consistently outperform prior art in terms of ability to converge to a valid solution, amount and distribution of singular mesh edges, and element count. Last but not least, we publicly release our code and reveal a conspicuous amount of technical details that were overlooked in previous literature, lowering an entry barrier that was hard to overcome for practitioners in the field.

Evaluation of Deep Learning Methods in a Dual Prediction Scheme to Reduce Transmission Data in a WSN.

One of the most important challenges in Wireless Sensor Networks (WSN) is the extension of the sensors lifetime, which are battery-powered devices, through a reduction in energy consumption. Using data prediction to decrease the amount of transmitted data is one of the approaches to solve this problem. This paper provides a comparison of deep learning methods in a dual prediction scheme to reduce transmission. The structures of the models are presented along with their parameters. A comparison of the models is provided using different performance metrics, together with the percent of points transmitted per threshold, and the errors between the final data received by Base Station (BS) and the measured values. The results show that the model with better performance in the dataset was the model with Attention, saving a considerable amount of data in transmission and still maintaining a good representation of the measured data.

Adjoint complement to the volume-of-fluid method for immiscible flows

The paper is concerned with an adjoint complement to the Volume-of-Fluid (VoF) method for immiscible two-phase flows, e.g. air and water, which is widely used in marine engineering due to its computational efficiency. The particular challenge of the primal and the corresponding adjoint VoF-approach refers to the sharp interface treatment featuring discontinuous physical properties. Both the continuous adjoint two-phase system (integration-by-parts) and the corresponding dual compressive convection schemes (summation-by-parts) are derived for two prominent compressive convection schemes, namely the High Resolution Interface Capturing Scheme (HRIC) and Compressive Interface Capturing Scheme for Arbitrary Meshes (CICSAM). The dual scheme rigorously mirrors the primal Normalized-Variable-Diagram (NVD) stencils. Attention is restricted to steady state applications. Thus both the primal and the dual procedures are performed in pseudo-time and the backward integration of the dual approach is performed around the (pseudo-temporal) converged primal field. Therefore, the adjoint system experiences the same time step size restrictions as the primal system, is independent of the primal time horizon and forms a robust as well as an a priori stable adjoint solution process.The paper analyses the primal and adjoint equations for an engineering model problem. An analytical solution to the model problem is initially presented, which displays that the adjoint part does not offer a unique, non-trivial solution. As a remedy, an additional diffusive concentration term is introduced to the adjoint concentration equation. The imposed heuristic modification violates the dual consistency but strongly regularizes the solution of the adjoint system. The modification can be justified by reference to phase-separating diffuse-interface models and inheres a free mobility-parameter. Numerical results obtained from the modified approach are benchmarked against the analytical solution for the model problem. Supplementary, the influence of the modification on the sensitivities obtained from simulations for the two-dimensional flow around a submerged hydrofoil at Froude and Reynolds numbers of practical interest are discussed for a range of mobility-parameters. The final application refers to a shape-optimization of a generic 3D underwater vehicle and underlines a negligible influence of the free mobility parameter, even for an objective functional that directly depends on the manipulated (dual) field quantity.

Convergence analysis of modified [formula omitted]th power Lagrangian algorithms with alternative updating strategies for constrained nonconvex optimization

In this paper, we present new convergence properties of the primal–dual methods based on the pth power Lagrangian function for inequality-constrained nonconvex optimization problems. Convergence to a global optimal solution is first established for a basic primal–dual scheme under a mild condition, without requiring the boundedness condition of the multiplier sequence. Modified pth power Lagrangian methods based on three different algorithmic strategies are then proposed. We show that the same convergence of three modified algorithms can be ensured under weaker conditions. Finally, we present some preliminary numerical results for three modified pth power Lagrangian algorithms.

A dual scheme for solving linear countable semi-infinite fractional programming problems

Using a dual method for solving linear fractional programming problems, we propose an approach to find optimal solutions of linear countable semi-infinite fractional programming problems via optimizing sequences. Duality theorems are established. A dual scheme for solving linear countable semi-infinite fractional problems is proposed. Examples are provided.

A Dual Active-Passive Coating with Intumescent and Fire-Retardant Properties Based on High Molecular Weight Tannins

In this study, the tannins extracted from the Pinus radiata bark were used to develop an active–passive dual paint scheme with intumescent (IN) and fire-resistant (FR) behaviors. The properties of the coating were observed to depend on the concentration of high-molecular-weight tannins (H-MWT) incorporated into the formulation. At high concentrations (13% w/w), the coating exhibits fire-retardant properties due to the generation of a carbonaceous layer; however, at low concentrations (2.5% w/w), it generates an intumescent effect due to the formation of a carbonaceous foam layer. The dual IN–FR scheme was evaluated against fire by flame advance tests, carbonization index, mass loss, and intumescent effect, and was also compared to a commercial coating. The dual scheme presented good mechanical properties with a pull-off adhesion value of 0.76 MPa and an abrasion index of 54.7% at 1000 cycles, when using a coating with a high solid content (>60%) and the same thickness as those of the commercial coatings. The results of the fire resistance test indicate that the dual scheme generates a protective effect for wood and metal, with an excellent performance that is comparable to that of a commercial intumescent coating.