The adaptable choosability of a multigraph G $G$, denoted cha(G) ${\text{ch}}_{a}(G)$, is the smallest integer k $k$ such that any edge labelling, τ $\tau $, of G $G$ and any assignment of lists of ...size k $k$ to the vertices of G $G$ permits a list colouring, σ $\sigma $, of G $G$ such that there is no edge e=uv $e=uv$ where τ(e)=σ(u)=σ(v) $\tau (e)=\sigma (u)=\sigma (v)$. Here we show that for a multigraph G $G$ with maximum degree Δ ${\rm{\Delta }}$ and no cycles of length 3 or 4, cha(G)≤(22+o(1))Δ∕ln Δ ${\text{ch}}_{a}(G)\,\le (2\sqrt{2}+o(1))\sqrt{{\rm{\Delta }}\unicode{x02215}\mathrm{ln}\unicode{x0200A}{\rm{\Delta }}}$. Under natural restrictions we can show that the same bound holds for the conflict choosability of G $G$, which is a closely related parameter recently defined by Dvořák, Esperet, Kang and Ozeki.
Natural gas transportation predominantly utilizes pipelines, and the safety of these systems largely hinges on the integrity of girth welds. However, once pipelines are buried post-construction, ...pinpointing weld inspection sites becomes complex. Presently, weld risk assessments rely on costly and specialized inspections. Hence, enhancing the accuracy in identifying defective welds and discovering superior inspection techniques is paramount. Our research employed machine learning, specifically an ensemble model of RandomForest and CatBoost, to prioritize weld inspections. After analyzing the West-East Gas Pipeline Girth Weld Dataset and addressing data imbalances using the SMOTE technique, we refined the model parameters. The culminating model yielded an F1-score of 0.815 and an average accuracy of 0.836, outperforming standalone models. Employing the SHAP method improved the model’s transparency, facilitating a more informed decision-making process regarding pipeline inspections. This study underscores the potential of machine learning in elevating oil and gas pipeline safety measures.
•Feature engineering was conducted on the pipeline girth weld dataset, employing a spectrum of advanced methods.•Combined two tree integration strategies in an ensemble classification model.•Optimized model parameters using dual strategies for comprehensive tuning.•The model was interpreted within the framework of SHapley Additive exPlanations (SHAP).
On strictly chordality-k graphs Dhanalakshmi, S.; Sadagopan, N.
Discrete Applied Mathematics,
06/2020, Volume:
280
Journal Article
Peer reviewed
Open access
Strictly Chordality-k graphs (SCk graphs) are graphs which are either cycle free or every induced cycle is exactly k, for some fixed k,k≥3. Note that k=3 and k=4 are precisely the Chordal graphs and ...Chordal Bipartite graphs, respectively. In this paper, we initiate a structural and an algorithmic study of SCk,k≥5 graphs.
In this letter we propose a new approach to generation of regular QC-LDPC codes with girth up to 12. The aim of the proposed smart exhaustive search (SES) algorithm is to construct codes with the ...desired lifting factor or to check whether codes with this parameter even exist. We define new lower bounds on the lifting degree as a necessary condition for the lifted graph to have a certain girth from fully connected base graphs. This modification opens space for improvement of the lifting factor minimisation problem for QC-LDPC code construction. With a more precisely defined search region it is possible to achieve better results with existing algorithms.
Summary
Background
Causes of abnormal behaviour during tacking‐up or mounting are multifactorial, but may be associated with an ill‐fitting saddle, a rider sitting on the caudal third of the saddle, ...or lameness.
Objectives
To determine whether: (1) owners believed their horse showed abnormal behaviour when tacked‐up or mounted; (2) this agreed with observations by a veterinarian.
Study design
Cross‐sectional study; convenience sample.
Methods
Horses were undergoing prepurchase examinations, investigation of poor performance, or were recruited by invitation. Owners were asked if their horse showed abnormal behaviour when tacked‐up or mounted and subsequently whether they showed specific behaviours (yes/no) during bridling, saddling, girthing and mounting. Each horse was observed during tacking‐up and mounting by one veterinarian who recorded the occurrence of each behaviour. Agreement between the owners and the veterinarian was evaluated using intraclass correlation (ICC) coefficients with 95% confidence intervals (CI).
Results
Overall 34.2% (66/193) of owners reported that their horse showed behavioural abnormalities during tacking‐up or mounting. There was poor to good agreement between the owners and veterinarian for horses putting their head up to avoid bridling (ICC 0.53, CI 0.37, 0.64) and being reluctant to open their mouth for the bit (ICC 0.52, CI 0.36, 0.64). There was poor to fair agreement for evading noseband tightening (ICC 0.41, CI 0.21, 0.56), elevating the head (ICC 0.24, CI 0.00, 0.43) and teeth grinding (ICC 0.23, CI 0.00, 0.42). For attempts to bite, there was fair to excellent agreement during saddling (ICC 0.67, CI 0.56, 0.75) and good to excellent agreement during girthing (ICC 0.73, CI 0.64, 0.79). Results for some behaviours suggested potential systematic disagreement between the veterinarian and owners.
Main limitations
Potential bias of volunteers recruited by invitation. Day‐to‐day variation of behaviours is unknown.
Conclusions
The majority of owners were unaware that their horses showed behavioural abnormalities during tacking‐up or mounting.
Necrotizing enterocolitis (NEC) is a disease of prematurity resulting in surgery for approximately 30% of patients. Trends in abdominal distention can assist decision-making. There is no defined ...abdominal girth change that predicts need for surgery. The aim of this study was to determine any relationship between girth change and surgery for NEC.
An IRB-exempt review of NEC patients from 2015 to 2020 at a single institution was performed. Inclusion and exclusion criteria were applied. Demographics, daily largest girth, and laboratory data were recorded. Average daily%girth change was calculated, as was largest%change from first girth of NEC episode. Statistical analysis was performed using Mann-Whitney U tests and ROC curve (p<0.05).
43/178 patients were analyzed. 30% underwent surgery. There was a statistically significant difference in average daily%girth change between medical and surgical patients based on <30 and >30 week gestational age; this significance persisted when analyzing birth weight. Laboratory data was non-contributory. Further subgrouping did not yield appropriate sample sizes for analysis. Threshold to predict surgery was a 1.2% daily girth increase based on ROC analysis.
Abdominal girth changes differed significantly between medical and surgical NEC. Establishing a threshold for%change in girth would be valuable for NEC management to assist in surgery decision-making; the value found in this study may be within measurement error. However, any girth increase put the patient at risk for surgery. Abdominal girths should continue to be included in surgical decision-making for premature infants with NEC.
The expansion of the area for the cultivation of rubber plants is hampered by the fact that the availability of mineral land has begun to decrease, so many have started to plant rubber on marginal ...lands such as peatlands. Peatlands for agriculture have many limiting factors, but if peatlands are adequately managed with drainage as well as ameliorant and fertilizing inputs, then peatlands have the potential to be used as agricultural land. However, information on research results related to rubber cultivation on peatlands is still very limited, so this study was carried out to observe the growth of rubber plants of PB 260 clones on peatlands. The research was carried out for five years in Sungai Rengit Village, South Sumatra, using rubber planting material in a polybag of PB 260 clones. The observations' parameters were stem girth, peat water level, and peat subsidence. The results showed that the growth of PB 260 clones during the immature plant period on peatland was not significantly different from rubber plants on mineral soils. At the research location, there was never any puddle and the peat water level was maintained because the drainage channels were well made. During the five years of observation, the highest peat water level occurred in the rainy season at 27 cm from the peat surface, while the lowest peat water level occurred in the dry season, which was more than 150 cm from the peat surface. The peat decline reached 25 cm during the five years of observation
Assume k $k$ is a positive integer, λ={k1,k2,…,kq} $\lambda =\{{k}_{1},{k}_{2},\ldots ,{k}_{q}\}$ is a partition of k $k$ and G $G$ is a graph. A λ $\lambda $‐assignment of G $G$ is a k ...$k$‐assignment L $L$ of G $G$ such that the colour set ⋃v∈V(G)L(v) ${\bigcup }_{v\in V(G)}L(v)$ can be partitioned into q $q$ subsets C1∪C2∪⋯∪Cq ${C}_{1}\cup {C}_{2}\cup \cdots \,\cup {C}_{q}$ and for each vertex v $v$ of G $G$, ∣L(v)∩Ci∣=ki $| L(v)\cap {C}_{i}| ={k}_{i}$. We say G $G$ is λ $\lambda $‐choosable if for each λ $\lambda $‐assignment L $L$ of G $G$, G $G$ is L $L$‐colourable. In particular, if λ={k} $\lambda =\{k\}$, then λ $\lambda $‐choosable is the same as k $k$‐choosable, and if λ={1,1,…,1} $\lambda =\{1,1,\ldots ,1\}$, then λ $\lambda $‐choosable is equivalent to k $k$‐colourable. For the other partitions of k $k$ sandwiched between {k} $\{k\}$ and {1,1,…,1} $\{1,1,\ldots ,1\}$ in terms of refinements, λ $\lambda $‐choosability reveals a complex hierarchy of colourability of graphs. Assume λ={k1,…,kq} $\lambda =\{{k}_{1},\ldots ,{k}_{q}\}$ is a partition of k $k$ and λ′ $\lambda ^{\prime} $ is a partition of k′≥k $k^{\prime} \ge k$. We write λ≤λ′ $\lambda \le \lambda ^{\prime} $ if there is a partition λ″={k1″,…,kq″} $\lambda ^{\prime\prime} =\{{k}_{1}^{^{\prime\prime} },\ldots ,{k}_{q}^{^{\prime\prime} }\}$ of k′ $k^{\prime} $ with ki″≥ki ${k}_{i}^{^{\prime\prime} }\ge {k}_{i}$ for i=1,2,…,q $i=1,2,\ldots ,q$ and λ′ $\lambda ^{\prime} $ is a refinement of λ″ $\lambda ^{\prime\prime} $. It follows from the definition that if λ≤λ′ $\lambda \le \lambda ^{\prime} $, then every λ $\lambda $‐choosable graph is λ′ $\lambda ^{\prime} $‐choosable. It was proved in Zhu that the converse is also true. This paper strengthens this result and proves that for any λ≰λ′ $\lambda \,\le \unicode{x00338}\,\lambda ^{\prime} $, for any integer g $g$, there exists a graph of girth at least g $g$ which is λ $\lambda $‐choosable but not λ′ $\lambda ^{\prime} $‐choosable.
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