Set Of Problems Research Articles

How to arrange the robotic environment? Leveraging experience in both motion planning and environment optimization

This study presents an experience-based hierarchical-structure optimization algorithm to address the robotic system environment design problem, which combines motion planning and environment arrangement problems together. The motion planning problem, which could be defined as a multiple-degree-of-freedom (m-DOF) problem, together with the environment arrangement problem, which could be defined as a free DOF problem, is a high-dimensional optimization problem. Therefore, the hierarchical structure was established, with the higher layer solving the environment arrangement problem and lower layer solving the problem of motion planning. Previously planned trajectories and past results for this design problem were first constructed as datasets; however, they cannot be seen as optimal. Therefore, this study proposed an experience-reuse manner, which selected the most “useful” experience from the datasets and reused it to query new problems, optimize the results in the datasets, and provide better environment arrangement with shorter path lengths within the same time. Therefore, a hierarchical structural caseGA-ERTC algorithm was proposed. In the higher layer, a novel approach employing the case-injected genetic algorithm (GA) was implemented to tackle optimization challenges in robot environment design, leveraging experiential insights. Performance indices in the arrangement of the robot system’s environment were determined by the robotic arm’s motion and path length calculated using an experience-driven random tree (ERT) algorithm. Moreover, the effectiveness of the proposed method is illustrated with the 12.59% decrease in path lengths by solving different settings of hard problems and 5.05% decrease in easy problems compared with other state-of-the-art methods in three small robots.

Comparing options for screening of reading difficulties in middle school: Do teacher ratings improve accuracy?

Reading problems may emerge beyond the primary grades when the linguistic and cognitive demands of reading comprehension increase in middle school. The accurate identification of students requiring supplemental reading instruction is critical to provide remediation and decrease the prevalence and likelihood of reading problems in secondary settings and beyond. Nevertheless, research guidance on middle school reading screening is scarce. This study analyzed data from 193 sixth-grade students across 12 classrooms to examine (a) how well various reading screeners predicted proficiency on the year-end state assessment, (b) what combinations of reading screeners were most accurate, (c) the extent to which a brief teacher rating improved classification accuracy, and (d) the agreement rates between the most accurate combinations of screeners. Screeners included the Sight Word Efficiency, oral reading fluency (ORF), maze, and a multiple-choice reading comprehension (MCRC) assessment. Results from logistic regressions and receiver operating characteristic curve analyses suggested that no single screener was appropriate for use and that combinations of two or three screeners assessing different reading skills improved classification accuracy (i.e., ORF + MCRC, ORF + maze + MCRC). Moreover, teacher ratings further improved classification accuracy but its predictive value depended on the combination of screeners. Finally, there was a high agreement regarding which students were identified as needing intervention between these combinations of screeners. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Horizon problem and capital expenditures: evidence from the public sector in Indonesia

PurposeThis study investigates whether horizon problems affect the allocation of capital budgets and their implementation in a government setting.Design/methodology/approachWe use data from 2005 to 2020 for local governments in Indonesia, which apply a limit of two five-year terms for mayors. We use regression analyses for panel data with total observations of 4,541 local government years from 448 unique local governments. We also use graphical analyses and t-tests to provide robustness to our results.FindingsMayors allocated lower capital expenditures in the second term than in the first. Capital budget allocation is lower for local governments whose mayors are older than 60. Our additional analysis shows that incumbents seeking re-election allocate more capital expenditure than those not seeking re-election.Research limitations/implicationsThis study contributes to the literature on the behavioral effect of term limits on local government's allocation and implementation of capital budgets. Limiting elected government officials to a certain number of terms will prevent the monopoly of power. However, it may negatively affect budget allocation on capital programs in their last term. Our findings should interest public policymakers in discerning the costs and benefits of term limits for elected offices.Originality/valueMost studies on horizon problems have focused on the corporate setting. This study provides evidence of the effects of horizon problems in the government setting, especially in Asia.

Mathematical Techniques in the Design of Robust Control Systems

Solid control frameworks are exceptionally imperative for making beyond any doubt that energetic frameworks remain steady and work well in a parcel of diverse circumstances and with a parcel of questions. This diagram tells you everything you wish to know about the numerical strategies utilized to form steady control systems. Strong control tries to bargain with issues like unknowns within the system model, stuns from the exterior, and changes within the system's parameters. It does this to form beyond any doubt that the framework keeps working well and remaining steady in spite of these issues. Lyapunov soundness hypothesis and the H-infinity (H∞) optimization strategy are two of the foremost critical arithmetic apparatuses. Lyapunov steadiness hypothesis gives us a way to see at how steady a framework is, and H∞ minimizes the worst-case pick up from unsettling influence to yield. State-space representations are moreover utilized to show and ponder multi-input multi-output (MIMO) frameworks, which makes control plan more organized. When making controls that guarantee steady execution, strategies like Direct Framework Disparities (LMIs) and Riccati conditions are utilized. The thought of unwavering quality limits is additionally displayed to degree how well the framework can handle factors. The solid control plan incorporates frequency-domain apparatuses, such as the Nyquist and Bode plots, to see at how the framework acts at distinctive frequencies. This makes it simpler to form controllers that can bargain with high-frequency occasions. We conversation around progressed strategies like α-synthesis and strong shaft situation that can offer assistance with certain control problems in dubious settings. Down to earth illustrations appear how these scientific strategies can be used, showing how vital they are in numerous building areas, such as the airplane, vehicle, and prepare control industries. The unique emphasizes how imperative these numerical strategies are for making beyond any doubt that solid control frameworks can handle the challenges of the genuine world, which improves system security, execution, and steadfastness in a wide run of circumstances. The abstract's objective with this outline is to provide you a basic idea of the math that's critical to the field of solid control framework plan.

Co-existence of antibiotic resistance and virulence factors in carbapenem resistant Klebsiella pneumoniae clinical isolates from Alexandria, Egypt.

The emergence and spread of carbapenem resistance among Enterobacteriaceae, particularly Klebsiella pneumoniae, constitute a serious threat to public health, since carbapenems are the last line of defense in the treatment of life-threatening infections caused by drug-resistant Enterobacteriaceae. The current study investigated the co-existence of different virulence factors and carbapenemases in carbapenem-resistant Klebsiella pneumoniae clinical isolates from Alexandria, Egypt. Phenotypic characterization of virulence factors indicated that 41.5% of the isolates were strong biofilm producers, while hypermucoviscosity was detected in 14.9% of the isolates. All isolates harbored five or more virulence factor encoding genes. entB, ycfM, mrkD and fimH were detected in all isolates, while only one isolate was negative for ybtS. uge, iutA, rmpA and kpn were detected in 61 (64.8%), 55 (58.5%), 41 (43.6%) and 27 (28.7%) isolates, respectively, while all isolates lacked magA and k2A. Phenotypic detection of carbapenemases was explored by performing CarbaNP and mCIM/eCIM. CarbaNP test showed positive results in 98.9% of the isolates and positive mCIM tests were observed in all isolates, while 68 (72.3%) isolates showed positive eCIM tests. blaNDM was the most prevalent carbapenemase encoding gene (92.5%) followed by the blaOXA-48 (51.1%), while blaKPC was detected in only one (1.06%) isolate. blaVIM, blaIMP and blaGES were not detected in any of the tested isolates. The widespread of carbapenem-resistant Klebsiella pneumoniae represents a major problem in health care settings. A significant association between certain virulence factors and carbapenemase-encoding genes was observed. Antibiotic stewardship programs and infection control policies should be effectively implemented especially in hospitals to limit the spread of such highly virulent pathogens.

Guanabenz acetate, an antihypertensive drug repurposed as an inhibitor of Escherichia coli biofilm.

Biofilm-associated bacterial infections are one of the major problems in medical settings. There are currently limited biofilm inhibitors available for clinical use. Guanabenz acetate, a drug used to treat high blood pressure, was found to be an effective anti-biofilm agent against Escherichia coli. Our results show that this drug can inhibit the production of cellulose and curli amyloid protein, which are the two main components of E. coli biofilms. Our findings highlight the possibility of repurposing a drug to prevent E. coli biofilm formation.

Digital-analog counterdiabatic quantum optimization with trapped ions

Abstract We introduce a hardware-specific, problem-dependent digital-analog quantum algorithm of a counterdiabatic quantum dynamics tailored for optimization problems. Specifically, we focus on trapped-ion architectures, taking advantage from global Mølmer–Sørensen gates as the analog interactions complemented by digital gates, both of which are available in the state-of-the-art technologies. We show an optimal configuration of analog blocks and digital steps leading to a substantial reduction in circuit depth compared to the purely digital approach. This implies that, using the proposed encoding, we can address larger optimization problem instances, requiring more qubits, while preserving the coherence time of current devices. Furthermore, we study the minimum gate fidelity required by the analog blocks to outperform the purely digital simulation, finding that it is below the best fidelity reported in the literature. To validate the performance of the digital-analog encoding, we tackle the maximum independent set problem, showing that it requires fewer resources compared to the digital case. This hybrid co-design approach paves the way towards quantum advantage for efficient solutions of quantum optimization problems.

Using an app-based screening tool to predict deficits in written word spelling at school entry

IntroductionThe first year of schooling is crucial for the further development of spelling abilities in children, which makes early assessment and intervention essential. The aim of this study was to develop and validate an efficient and cost-free screening tool for identifying spelling problems in community school settings around the time of school entry.MethodsA broad range of precursors of spelling (vocabulary, grammar, letter knowledge, phonological awareness, phonological working memory, rapid automatized naming) were assessed in 522 Austrian first graders (6–7 years of age) in the first weeks of schooling. At the end of first grade, spelling abilities were assessed by newly developed spelling tasks based on the trochaic foot. By applying logistic regression with the least absolute shrinkage and selection operator (LASSO), we aimed to select a set of important predictors of spelling problems at the end of grade 1 (i.e., scoring below the 16th percentile in the spelling test).ResultsOur analysis identified letter knowledge (i.e., an aspect of phonological information processing) and sentence repetition (i.e., a measure of grammatical knowledge) as important predictors of spelling problems. The screening tool has acceptable diagnostic accuracy [area under the curve (AUC) = 0.0.725 and DeLong 95% CI (0.666, 0.784)]. Further analyses indicated that the AUC differs neither between boys and girls nor between children with and without German as their first language.DiscussionThese results suggest that administering the screening tool during the first weeks of schooling is a valid approach to identifying spelling deficits, which in turn enables early targeted pedagogical interventions. Practical implications for spelling instructions are discussed.

Efficiently Constructing Convex Approximation Sets in Multiobjective Optimization Problems

Convex approximation sets for multiobjective optimization problems are a well-studied relaxation of the common notion of approximation sets. Instead of approximating each image of a feasible solution by the image of some solution in the approximation set up to a multiplicative factor in each component, a convex approximation set only requires this multiplicative approximation to be achieved by some convex combination of finitely many images of solutions in the set. This makes convex approximation sets efficiently computable for a wide range of multiobjective problems: even for many problems for which (classic) approximations sets are hard to compute. In this article, we propose a polynomial-time algorithm to compute convex approximation sets that builds on an exact or approximate algorithm for the weighted sum scalarization and is therefore applicable to a large variety of multiobjective optimization problems. The provided convex approximation quality is arbitrarily close to the approximation quality of the underlying algorithm for the weighted sum scalarization. In essence, our algorithm can be interpreted as an approximate version of the dual variant of Benson’s outer approximation algorithm. Thus, in contrast to existing convex approximation algorithms from the literature, information on solutions obtained during the approximation process is utilized to significantly reduce both the practical running time and the cardinality of the returned solution sets while still guaranteeing the same worst-case approximation quality. We underpin these advantages by the first comparison of all existing convex approximation algorithms on several instances of the triobjective knapsack problem and the triobjective symmetric metric traveling salesman problem. History: Accepted by Andrea Lodi, Area Editor for Design & Analysis of Algorithms–Discrete. Funding: This research was supported by the German Research Foundation [Project 398572517]. Supplemental Material: The software that supports the findings of this study is available within the paper and its Supplemental Information ( https://pubsonline.informs.org/doi/suppl/10.1287/ijoc.2023.0220 ) as well as from the IJOC GitHub software repository ( https://github.com/INFORMSJoC/2023.0220 ). The complete IJOC Software and Data Repository is available at https://informsjoc.github.io/ .

An approximation algorithm for the prize-collecting connected dominating set problem

An approximation algorithm for the prize-collecting connected dominating set problem

An overhaul cycle performance degradation modeling method for marine gas turbines

A degradation modeling method of marine gas turbines for the overhaul cycle is proposed to address the problem of insufficient data sets for fault diagnosis and trend prediction algorithm validation. First, a nonlinear model of the marine three-shaft gas turbine gas path was established. The degradation path and component degradation models were subsequently obtained. The distribution of the washing cycle and degradation factors in the overhaul cycle were solved using an optimization algorithm, and degradation data in the washing cycle were obtained. The model's feasibility is validated with a segment of actual degradation data. The change rule of the gas turbine operating data during the overhaul cycle was also obtained. The degradation data of marine gas turbines under different boundary conditions are simulated using the established degradation model. This model provides data sets essential for validating fault diagnosis and trend prediction algorithms. Furthermore, it provides a reference for modeling the degradation of other mechanical equipment.

Exact algorithms for maximum independent set problem on hypergraphs

Exact algorithms for maximum independent set problem on hypergraphs

Validity and reliability of the Japanese version of the Substance Use Stigma Mechanism Scale.

Stigma against people who have alcohol and drug problems severely affects their health and well-being. An instrument based on stigma theory assessing individual-level stigma is essential for a comprehensive understanding of their stigma. We evaluated the validity and reliability of the Japanese version of the Substance Use Stigma Mechanism Scale (SU-SMS-J) among a population who had alcohol or drug use problems. Adults with experience in substance use disorders from psychiatry outpatient departments and rehabilitation facilities participated in the self-administered questionnaire survey. Confirmatory factor analysis was conducted to test the structural validity of the 5-factor model proposed in other language versions, and factor loadings and correlation between the subscales were confirmed. The correlations between the SU-SMS-J and psychometric properties related to substance use (e.g., severity of substance use, motivation to change) were investigated to assess concurrent validity. Internal consistency was assessed using Cronbach's alpha coefficients. Data from 126 participants were analyzed. The 5-factor model was acceptable with good or reasonable model fit indices. The correlations between subscales were weak to moderate, and this result suggested the SU-SMS-J assessed different but related components of stigma: enacted, anticipated, and internalized stigma from different stigma sources (family and healthcare workers). The SU-SMS-J and subscales showed moderate concurrent validity. Internal consistency was mostly sufficient, with Cronbach's alpha coefficients of 0.86 for all items and 0.66-0.93 for subscales. The SU-SMS-J is valid and reliable for use among populations with substance use problems in various settings in Japan.

Students’ commognitive conflicts in solving absolute value inequalities

The material of absolute value inequalities is considered more difficult to study. There are still many undergraduate students who still make mistakes in understanding and solving problems related to this topic. Moreover, some of them do not yet know how to read the symbols. Therefore, these issues need to be studied more thoroughly. This research was conducted to explore the undergraduate students’ discourse on absolute value inequality tasks through commognitive analysis. A qualitative approach was applied, involving 78 participants; 11 of them were further interviewed. The analysis of the absolute value inequality tasks and the interview results revealed that there were commognitive conflicts that needed to be addressed. The findings of this research showed that commognitive conflicts arose when the undergraduate students applied the definition of absolute value and determined the solution set for the absolute value inequality problems.

Non-existence of cusps for a free-boundary problem for water waves

In Varvaruca and Weiss (2011), Varvaruca and Weiss eliminate the existence of cusps for a free-boundary problem for two-dimensional water waves under assumptions that hold for solutions for which \{u>0\} is a “strip-like” domain in the sense of Varvaruca (2008). In this paper, it is proven that cusps do not exist in the natural setting for these free-boundary problems. In particular, non-strip-like domains are also allowed. This qualitative result follows from quantitative results which, roughly speaking, give lower bounds on the “slope” at which the free boundary approaches a stagnation point. This builds upon recent work on non-existence of cusps in McCurdy and Naples (2022) for local minimizers.

On greedy approximation algorithm for the minimum resolving dominating set problem

On greedy approximation algorithm for the minimum resolving dominating set problem

Existence and density theorems of Henig global proper efficient points

In this work, we provide some novel results that establish both the existence of Henig global proper efficient points and their density in the efficient set for vector optimization problems in arbitrary normed spaces. Our results do not require the assumption of convexity, and in certain cases, can be applied to unbounded sets. However, it is important to note that a weak compactness condition on the set (or on a section of it) and a separation property between the order cone and its conical neighbourhoods remains necessary. The weak compactness condition ensures that certain convergence properties hold. The separation property enables the interpolation of a family of Bishop-Phelps cones between the order cone and each of its conic neighbourhoods. This interpolation, combined with the proper handling of two distinct types of conic neighbourhoods, plays a crucial role in the proofs of our results, which include as a particular case other results that have already been established under more restrictive conditions.

Curriculum Reform of Preschool Education: An Innovative Path based on Gamification and Project-style Integration

This paper focuses on the curriculum reform of preschool education, and expounds the importance, purpose and challenges of preschool education curriculum reform under the background of educational needs in the new era. This paper analyzes the guiding significance of multiple intelligence theory, Montessori education method, gamification and project learning to preschool education courses. It is pointed out that there are some problems of single curriculum setting, limited teaching methods and means, and the challenges of teacher staff construction and resource allocation and concept change. This paper proposes the curriculum innovation of gamification and project-style integration, demonstrates its feasibility, expounds the design principles and implementation steps of the integrated curriculum, and makes a prospect for the future.

Construction of Virtual Experiment Teaching Platform based on 5E Teaching Mode and VI Technology

Virtual instruments have many advantages such as low cost, comprehensive functionality, easy scalability, and easy replication. At the same time, they can also meet the special requirements of time and space for remote experiments. Based on Web technology and virtual instrument technology, a virtual experiment system is constructed, which combines data sharing, remote control, and real-time operation. More conducive to utilizing experimental and scientific research resources. At the same time, virtual instruments have high flexibility and are no longer limited by traditional experimental teaching modes, which can save a lot of repeated investment costs. They can also keep the teaching equipment in the laboratory up-to-date and closely follow the development trend of science and technology. As a compulsory course for mechanical engineering majors, although the existing experimental system has achieved certain results, there are still limitations to 'Mechanical Engineering Testing Technology'. This article aims to address the problems of insufficient instrument sets and outdated equipment in the experimental teaching of "Mechanical Engineering Testing Technology", as well as students' poor ability to apply theory to practice and insufficient innovation ability. By integrating the 5E teaching mode, a virtual experimental teaching platform based on VI (Virtual Instrument) technology is established. Students can break through traditional experimental methods and conduct various experiments through the network, obtaining experimental experiences that are very similar to real experiments. At the same time, it can deepen their understanding and recognition of experiments, and better grasp theoretical knowledge.

Latent profiles of home behaviour problems in Trinidad and Tobago.

Caregivers who interact with children at home can provide a critical, complementary perspective on a child's behaviour functioning. This research used a parent-administered measure of problem behaviours to study perceptions of child behaviours across home situations. We applied latent profile analysis to identify subgroups of children with common behavioural tendencies in a nationally representative sample (N = 709) of 4- to 13-year-old children in Trinidad and Tobago. This study (a) identified latent profiles of children's over- and underactive behaviour problems in varied home settings and (b) examined how profile membership predicted academic skills and teacher-observed problem behaviours. The best-fitting four-profile model included one profile of adjusted behaviours (56%), one of the elevated attention-seeking behaviours (21%), a profile featuring withdrawn and disengaged behaviours (15%) and a relatively rare profile emphasising aggressive behaviours (8%). Children classified in the last profile displayed the poorest academic outcomes and the highest levels of teacher-observed behaviour problems.