Distance Problem Research Articles

Parameterized Inapproximability of the Minimum Distance Problem over All Fields and the Shortest Vector Problem in All \({\ell_{{p}}}\) Norms

Parameterized Inapproximability of the Minimum Distance Problem over All Fields and the Shortest Vector Problem in All \({\ell_{{p}}}\) Norms

Prediction of delayed breastfeeding initiation among mothers having children less than 2 months of age in East Africa: application of machine learning algorithms.

Delayed breastfeeding initiation is a significant public health concern, and reducing the proportion of delayed breastfeeding initiation in East Africa is a key strategy for lowering the Child Mortality rate. However, there is limited evidence on this public health issue assessed using advanced models. Therefore, this study aimed to assess prediction of delayed initiation of breastfeeding initiation and associated factors among women with less than 2 months of a child in East Africa using the machine learning approach. A community-based, cross-sectional study was conducted using the most recent Demographic and Health Survey (DHS) dataset covering the years 2011 to 2021. Using statistical software (Python version 3.11), nine supervised machine learning algorithms were applied to a weighted sample of 31,640 women and assessed using performance measures. To pinpoint significant factors and predict delayed breastfeeding initiation in East Africa, this study also employed the most widely used outlines of Yufeng Guo's steps of supervised machine learning. The pooled prevalence of delayed breastfeeding initiation in East Africa was 31.33% with 95% CI (24.16-38.49). Delayed breastfeeding initiation was highest in Comoros and low in Burundi. Among the nine machine learning algorithms, the random forest model was fitted for this study. The association rule mining result revealed that home delivery, delivered by cesarean section, poor wealth status, poor access to media outlets, women aged between 35 and 49 years, and women who had distance problems accessing health facilities were associated with delayed breastfeeding initiation in East Africa. The prevalence of delayed breastfeeding initiation was high. The findings highlight the multifaceted nature of breastfeeding practices and the need to consider socioeconomic, healthcare, and demographic variables when addressing breastfeeding initiation timelines in the region. Policymakers and stakeholders pay attention to the significant factors and we recommend targeted interventions to improve healthcare accessibility, enhance media outreach, and support women of lower socioeconomic status. These measures can encourage timely breastfeeding initiation and address the identified factors contributing to delays across the region.

An improving integration-enhanced ZNN for solving time-varying polytope distance problems with inequality constraint

An improving integration-enhanced ZNN for solving time-varying polytope distance problems with inequality constraint

Governing Over Distance: Delegating Trust and Dealing with Disorder in the Early East India Company Trade

ABSTRACT This study uses an overlooked case to reveal how the problem of distance shaped the early English East Indies trade. In 1617, preacher William Lesk returned to London from Surat. He had been sent to be a moral leader for East India Company factors, but they returned him when his scandalous behaviour threatened the survival of the Company’s trade in the Mughal empire. The social circumstances of the factory had real, material consequences. The factors sent signed eyewitness accounts of his misdeeds for Company leaders to address, but in London, Lesk’s claims of first-hand knowledge of the East Indies trade and affairs in Surat, along with savvy use of the politics of publicity, meant that Company leaders found him challenging to deal with. The story of Lesk reveals how managing distance required compromises on how best to govern the East Indies trade. Distance shaped how Company leaders interpreted events in the East Indies, while also opening up avenues for resisting Company judgements. Distance informed every aspect of the Company’s operation – not just economic but also social and political – and is essential to understanding how and why the Company developed as it did, both in the East Indies and London.

Advanced image stitching method and evaluation for underwater structure inspection utilizing planar array cameras

The inspection of underwater structural health is crucial for comprehensive bridge health assessments. In underwater structure imaging, traditional methods include single-camera and binocular camera inspection. However, due to water turbidity and long working distances with a small field-of-view, obtaining clear and high-quality detection images with these methods takes much work. To address this problem, this paper presents a method for planar array image stitching based on Harris corner point extraction, utilizing the advantages of planar array cameras characterized by short working distances and wide field-of-view. The core contribution of this paper is the introduction of an innovative image sequence stitching algorithm utilizing Harris corner point extraction and the combination of the first proposed planar array cameras with the image sequence stitching algorithm, which solves the problem of long distance and small field-of-view during the underwater inspection. The image stitching method involves calibrating camera parameters with a checkerboard and stitching underwater images from planar array cameras to reveal underwater structural features. Furthermore, five quantitative evaluation metrics and the method for calculating the field-of-view loss rate are presented to evaluate and analyze the stitched images. A series of experiments were performed on concrete surfaces, aquatic and underwater, with a total field-of-view of the underwater image after stitching of 358.86 mm × 319.24 mm at a working distance of 160 mm. Five evaluation methods were used to quantitatively evaluate the quality of the stitched images and calculate the field-of-view loss rate of the images. The results indicate that the proposed method improves the ability to inspect underwater. The stitched images achieve notable metrics: an entropy of approximately 6.7, an average gradient of about 1.7, a spatial frequency of around 3.5, an edge strength of about 17, mutual information of approximately 1.2, and a field-of-view loss rate of <0.1, facilitating more effective underwater structure inspection.

Inequity in unmet health care needs of women and children in India: A barrier to sustainable development goals in health

AbstractDespite progress in maternal and child health, significant gap and high inequity persist in unmet health needs, creating a barrier to universal health coverage. Previous studies have analysed inequity of health outcomes and healthcare availability, but limited research is available on delayed or not‐seeking treatment. Research conducted on unmet treatment lacks emphasis on vulnerable groups; women and children. The objective is to fill this research gap by estimating the contribution of socio‐economic factors to inequality in the unmet health needs of women and children. This study uses the concentration index, concentration curve and horizontal inequity index to estimate inequality. A decomposition analysis is conducted to estimate the contribution of each socio‐economic factor to inequality. The need‐adjusted index shows the inequity due to non‐need factors. The unmet health needs are significantly higher among socioeconomically disadvantaged groups. In addition to wealth, factors such as caste (4.43% and 7.23%), education (7.27% and 13.05%), media exposure (3.88% and 6.39%) and distance problem (5.35% and 14.61%) contribute to the inequity for both women and children. A negative horizontal inequity index confirms that non‐need factors are major contributors to inequity. Findings add new theoretical insights on healthcare accessibility and inform policymakers on factors creating disadvantages in treatment‐seeking. Action plans for universal health coverage need to incorporate social and institutional factors in policy and budgetary allocations. Further, health‐card system, health‐record‐keeping practices and community‐health officer/clinic can improve treatment seeking.

On Optimal Point Sets Determining Distinct Triangles

Erdős and Fishburn studied the maximum number of points in the plane that span $k$ distances (i.e. the set of pairwise distances between points has cardinality $k$) and classified these configurations, as an inverse problem of the Erdős distinct distances problem. We consider the analogous problem for triangles. Past work has obtained the optimal sets for one and two distinct triangles in the plane. In this paper, we resolve a conjecture that at most six points in the plane can span three distinct triangles, and obtain the hexagon as the unique configuration that achieves this. We also provide evidence that optimal sets cannot be on the square lattice in the general case.

Teaching uzbek as a second/foreign language in online classroom

Distance learning, sometimes called e-leaming, is a formalized teaching and learning system specifically designed to be carried out remotely by using electronic communication. Because distance learning is less expensive to support and is not constrained by geographic challenges, it offers opportunities in situations where traditional education sometimes faces difficulties in operating. Students under the press of scheduling or distance problems can benefit, as can employees, because distance education can be more flexible in terms of time and can be delivered virtually anywhere.

A matrix variant of the Erdős-Falconer distance problems over finite field

We study a matrix analog of the Erdős-Falconer distance problems in vector spaces over finite fields. We provide lower bounds for the cardinality of a subset of the matrix algebra over a finite field such that its distance set is the whole matrix algebra. There arises an interesting analysis of certain quadratic matrix Gauss sums.

Compressive Strength Of Concrete The Time Setting Of Application Of Plastiment® P-121 Additive Mixture

Infrastructure growth requires large quantities of concrete, a problem of concern distance between the batching plant and location of different casting locations, the process mixing and transporting to casting location requires time that can exceed the cement setting time. Plastiment helps improve the strength, durability and general quality of concrete. This research aims to determine the compressive strength of concrete at setting times of 60, 90 and 120 minutes using 150 mm x 300 mm specimens with variations in addition of plastiment of 0.20% and 0.40% of the cement weight. Primary data the form of material testing data and concrete compressive strength for each variation and secondary data is in the form of additives and the properties of cement used. The test results show that the compressive strength of concrete at 60, 90 and 120 minutes by adding Plastiment® P-121R at a variation of 0.20% is 17.55, 18.12 and 18.85 MPa while giving a dose of 0.40% is 17 .27, 19.82 and 22.08 MPa. Addition of plaster can meet the slump value requirements at each time variation and in contrast to normal concrete the slump value is not met at each time variation with the concrete having dried during mixing.

The Shortest Distance Problem: An Elementary Solution

Summary We offer an elementary solution to the shortest distance problem. In addition to being accessible to freshman Calculus students, our approach also provides a bit of extra information, namely a way quantify the “length excess” in terms of how much the path deviates from being a straight line.

Flanked Block-Interchange Distance on Strings.

Rearrangement sorting problems impact profoundly in measuring genome similarities and tracing historic scenarios of species. However, recent studies on genome rearrangement mechanisms disclosed a statistically significant evidence, repeats are situated at the ends of rearrangement relevant segments and stay unchanged before and after rearrangements.To reflect the principle behind this evidence, we propose flanked block-interchange, an operation on strings that exchanges two substrings flanked by identical left and right symbols in a string. The flanked block-interchange distance problem is formulated as finding a shortest sequence of flanked block-interchanges to transform a string into the other. We propose a sufficient and necessary condition for deciding whether two strings can be transformed into each other by flanked block-interchanges. This condition is linear time verifiable. Under this condition for two strings, we present a [Formula: see text]-approximation algorithm for the flanked block-interchange distance problem where each symbol occurs at most k times in a string and a polynomial algorithm for this problem where each symbol occurs at most twice in a string. We show that the problem of flanked block-interchange distance is NP-hard at last.

Recombinations, chains and caps: resolving problems with the DCJ-indel model

One of the most fundamental problems in genome rearrangement studies is the (genomic) distance problem. It is typically formulated as finding the minimum number of rearrangements under a model that are needed to transform one genome into the other. A powerful multi-chromosomal model is the Double Cut and Join (DCJ) model.While the DCJ model is not able to deal with some situations that occur in practice, like duplicated or lost regions, it was extended over time to handle these cases. First, it was extended to the DCJ-indel model, solving the issue of lost markers. Later ILP-solutions for so called natural genomes, in which each genomic region may occur an arbitrary number of times, were developed, enabling in theory to solve the distance problem for any pair of genomes. However, some theoretical and practical issues remained unsolved. On the theoretical side of things, there exist two disparate views of the DCJ-indel model, motivated in the same way, but with different conceptualizations that could not be reconciled so far. On the practical side, while ILP solutions for natural genomes typically perform well on telomere to telomere resolved genomes, they have been shown in recent years to quickly loose performance on genomes with a large number of contigs or linear chromosomes. This has been linked to a particular technique, namely capping. Simply put, capping circularizes linear chromosomes by concatenating them during solving time, increasing the solution space of the ILP superexponentially. Recently, we introduced a new conceptualization of the DCJ-indel model within the context of another rearrangement problem. In this manuscript, we will apply this new conceptualization to the distance problem. In doing this, we uncover the relation between the disparate conceptualizations of the DCJ-indel model. We are also able to derive an ILP solution to the distance problem that does not rely on capping. This solution significantly improves upon the performance of previous solutions on genomes with high numbers of contigs while still solving the problem exactly and being competitive in performance otherwise. We demonstrate the performance advantage on simulated genomes as well as showing its practical usefulness in an analysis of 11 Drosophila genomes.

On restricted Falconer distance sets

Abstract We introduce a class of Falconer distance problems, which we call of restricted type, lying between the classical version and its pinned variant. Prototypical restricted distance sets are the diagonal distance sets, k-point configuration sets given by $$ \begin{align*}\Delta^{\mathrm{diag}}(E)= \{ \,|(x,x,\dots,x)-(y_1,y_2,\dots,y_{k-1})| : x, y_1, \dots,y_{k-1} \in E\, \}\end{align*} $$ for a compact $E\subset \mathbb {R}^d$ and $k\ge 3$ . We show that $\Delta ^{\mathrm{diag}}(E)$ has non-empty interior if the Hausdorff dimension of E satisfies (0.1) $$ \begin{align} \dim(E)> \begin{cases} \frac{2d+1}3, & k=3, \\ \frac{(k-1)d}k,& k\ge 4. \end{cases} \end{align} $$ We prove an extension of this to $C^\omega $ Riemannian metrics g close to the product of Euclidean metrics. For product metrics, this follows from known results on pinned distance sets, but to obtain a result for general perturbations g, we present a sequence of proofs of partial results, leading up to the proof of the full result, which is based on estimates for multilinear Fourier integral operators.

Spatial patterns and determinants of low utilization of delivery care service and postnatal check-up within 2 months following birth in Ethiopia: Bivariate analysis.

Home delivery is a nonclinical childbirth practice that takes place in one's home with or without traditional birth attendants and postnatal care is the care given to the mother and her newborn baby; according to world health organization (WHO), the postnatal phase, begins one hour after birth and lasts six weeks (42 days). This paper aimed to study the spatial pattern and determinant factors of low utilization of delivery care (DC) services and postnatal check-up (PNC) after live births in Ethiopia. This study used the 2016 Ethiopian Demographic and Health Survey data as a source. A total weighted samples of 11023 women-children pairs were included. The bivariate binary logistic regression analyses with spatial effect were modeled using SAS version 9.4 and ArcGIS version 10.8 was used for mapping. The spatial distribution of low utilization of delivery care service and postnatal check-up were significantly clustered in Ethiopia (Moran's I statistic 0.378, P-value < 0.001 and 0.177, P-value < 0.001 respectively). Among 11023 children-women pair, the prevalence of home delivery and no postnatal check-up within two months following birth were 72.6% and 91.4% respectively. The Liben, Borena, Guji, Bale, Dolo and Zone 2 were predicted to have high prevalence of home delivery and part of Afder, Shabelle, Korahe, Dolo and Zone 2 were high risk areas of no postnatal checkup. Lack of occupation, region, large family size, higher birth order, low utilization of antenatal care visit, unable to access mass media, big problem of health facility distance and the spatial variable were found to be jointly significant predictors of low utilization of DC and PNC in Ethiopia. Whereas older age, being reside in rural area and low wealth status affects delivery care service utilization. We suggest health providers, policy makers and stakeholders consider those variables with priority given to Liben, Borena, Guji, Bale, Dolo, Zone 2, Afder, Shabelle and Korahe, where home delivery and no PNC were predicted relatively high. We also recommend researchers to conduct further studies using latest survey data set.

Investigating the complexity of the double distance problems

BackgroundTwo genomes mathbb {A} and mathbb {B} over the same set of gene families form a canonical pair when each of them has exactly one gene from each family. Denote by n_* the number of common families of mathbb {A} and mathbb {B}. Different distances of canonical genomes can be derived from a structure called breakpoint graph, which represents the relation between the two given genomes as a collection of cycles of even length and paths. Let c_i and p_j be respectively the numbers of cycles of length i and of paths of length j in the breakpoint graph of genomes mathbb {A} and mathbb {B}. Then, the breakpoint distance of mathbb {A} and mathbb {B} is equal to n_*-left( c_2+frac{p_0}{2}right). Similarly, when the considered rearrangements are those modeled by the double-cut-and-join (DCJ) operation, the rearrangement distance of mathbb {A} and mathbb {B} is n_*-left( c+frac{p_e }{2}right), where c is the total number of cycles and p_e is the total number of paths of even length.MotivationThe distance formulation is a basic unit for several other combinatorial problems related to genome evolution and ancestral reconstruction, such as median or double distance. Interestingly, both median and double distance problems can be solved in polynomial time for the breakpoint distance, while they are NP-hard for the rearrangement distance. One way of exploring the complexity space between these two extremes is to consider a sigma _k distance, defined to be n_*-left( c_2+c_4+ldots +c_k+frac{p_0+p_2+ldots +p_{k-2}}{2}right), and increasingly investigate the complexities of median and double distance for the sigma _4 distance, then the sigma _6 distance, and so on.ResultsWhile for the median much effort was done in our and in other research groups but no progress was obtained even for the sigma _4 distance, for solving the double distance under sigma _4 and sigma _6 distances we could devise linear time algorithms, which we present here.

Underground Canal Debris Detection System

This research tries to give a solution for one of the challenges that face the main and traditional irrigation system in Oman which is Falaj. The study will investigate the problem and will propose a modern solution that saves effort and costs and minimizes the risk on labor who are working on this system. The following report attempts to address the difficulty of accessing the dirt that occurs in the waters of the falaj and needs to be cleaned, because people will face the problem of distance and depth to reach this place, where they expose their lives to danger that may reach death. Therefore, the report proposes a solution to this problem, which is the design of the drone, which will detect dirt through Sending the image to the monitoring station of the device, and then the location of the cleaning is determined.

Partition Based Algorithms for Rearrangement Distances with Flexible Intergenic Regions.

Genome Rearrangement distance problems are used in Computational Biology to estimate the evolutionary distance between genomes. These problems consist of minimizing the number of rearrangement events necessary to transform one genome into another. Two commonly used rearrangement events are reversal and transposition. The first studied problems ignored nucleotides outside genes (called intergenic regions), or assumed that genomes have a single copy of each gene. Recent works made advancements in more general problems considering the number of nucleotides in intergenic regions, and replicated genes. Nevertheless, genomes tend to have wildly different quantities of nucleotides on their intergenic regions, which poses a problem when comparing these regions exactly. To overcome this limitation, our work considers some flexibility when matching intergenic regions that do not have the same number of nucleotides. We propose new problems seeking the minimum number of reversals, or reversals and transpositions, necessary to transform one genome into another, while considering flexible intergenic region information. We show approximations for these problems by exploring their relationship with the Signed Minimum Common Flexible Intergenic String Partition problem. We also present different heuristics for the partition problem, and conduct experimental tests on simulated genomes to assess the performance of our algorithms.

A note on the distinct distances problem in the hyperbolic plane

A note on the distinct distances problem in the hyperbolic plane

A Secure Multi-Party Computation Protocol for Graph Editing Distance against Malicious Attacks

The secure computation of the graph structure is an important element in the field of secure calculation of graphs, which is important in querying data in graphs, since there are no algorithms for the graph edit distance problem that can resist attacks by malicious adversaries. In this paper, for the problem of secure computation of similarity edit distance of graphs, firstly, the encoding method applicable to the Paillier encryption algorithm is proposed, and the XOR operation scheme is proposed according to the Paillier homomorphic encryption algorithm. Then, the security algorithm under the semi-honest model is designed, which adopts the new encoding method and the XOR operation scheme. Finally, for the malicious behaviors that may be implemented by malicious participants in the semi-honest algorithm, using the hash function, a algorithm for secure computation of graph editing distance under the malicious model is designed, and the security of the algorithm is proved, and the computational complexity and the communication complexity of the algorithm are analyzed, which is more efficient compared with the existing schemes, and has practical value. The algorithm designed in this paper fills the research gap in the existing literature on the problem of graph edit distance and contributes to solving the problem.