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Stemming plays a crucial role in natural language processing and information retrieval. It is challenging for the Gujarati language due to the complex morphology of several stemming algorithms for the Gujarati language that have been developed using rule-based, dictionary-based, or hybrid approaches. However, they are computationally expensive, produce more over-stemming errors and have limited accuracy. This paper introduces three novel optimized Gujarati stemmers using a trie data structure to overcome the above-mentioned limitations. The significant contributions to this paper are as follows. First, three optimized Gujarati stemmers, namely Optimized Gujarati Stemmer using Suffix Stripping Approach (OGS_SSA), Optimized Gujarati Stemmer using Rule-Based Approach (OGS_RBA), and Optimized Gujarati Stemmer using Re-parsing Based Approach (OGS_RPA), are proposed. Second, a novel algorithm to create a Gujarati dictionary using the trie data structure is proposed. Third, the proposed stemmers are rigorously assessed using three standard datasets, namely entertainment, health, and agriculture. The performance of the proposed stemmers is measured using evaluation parameters such as precision, recall, F 1 score, accuracy, number of stemming errors and processing time. The results show that OGS_RPA consistently exceeds the OGS_SSA and OGS_RBA for precision, recall, F 1 score, and accuracy. In addition, it exhibits a lower number of stemming errors. Moreover, the performance of the proposed stemmer is compared with the existing Gujarati hybrid stemmer. The results show a 14–16% improvement in accuracy and less processing time compared to the Gujarati hybrid stemmer. OGS_SSA demonstrated enhanced processing time, making it a feasible option for applications that prioritize prompt response time. Furthermore, it demonstrates 10–11% enhancement in accuracy and a reduction in processing time than the Gujarati hybrid stemmer. OGS_RBA exhibits moderate performance due to its rule-based methodology compared to OGS_RPA and OGS_SSA. However, it shows 10–13% improvement in accuracy than the Gujarati hybrid stemmer.

Nowadays, the blasting volume and the corresponding explosive demand have been increasing more and more with the continuous growth of open-pit mining projects. There is a substantial waste of explosive energy due to fly-rock and vibration in the blasting process. In order to maximize the utilization of explosive energy, the air-deck stemming structure is generally adopted. However, punching mechanism of the air-deck stemming structure is not revealed yet. In this study, the solution equation of punching height is first obtained to theoretically analyze the movement mechanism of blasthole stemming. Then, the effects of different stemming structures (air-deck stemming and conventional stemming) on the punch height and rock fragmentation are investigated by conducting three field experiments. Finally, the meshless smoothed particle hydrodynamics (SPH) model in ANSYS/AUTODYN module is employed to analyze the velocity of the stemming, the blasting pressure near the hole wall, and the rock fragmentation. The results show that: (1) compared with the conventional stemming structure, the air-deck stemming structure reduces the average punching height by 48–66%, which can mitigate the environmental hazards due to the blasting dust. (2) The size of the rock fragments in the conventional stemming area is significantly higher than the ones in the air-deck stemming area. The volume of the rock fragments with sizes smaller than 100 mm is 60–81% in the air-deck stemming area but only 24–45% in the conventional stemming area. (3) Compared with the conventional stemming, the blasting pressure increases by 1–2 times at the stemming part and decreases by 1.25–2 times at the charging part by using the air-deck stemming. The results show that the explosive energy can be effectively utilized by using the air-deck stemming structure, which provides significant guidance for the drilling blasting in the increasing open-pit mining projects.HighlightsThe solution equation of punching height can be deduced by Newton's law of inertia and the conservation of momentum principle through theoretical analysis.Three field experiments are conducted to study the effects of air-deck stemming and conventional stemming on the punching height and the rock fragmentation.The stemming velocity, the blasting pressure, and the rock fragmentation are analyzed using the meshless SPH model in AUTODYN module.

In this contribution we address the issue of efficient finite element treatment for phase-field modeling of brittle fracture. We start by providing an overview of the existing quasi-static and dynamic phase-field fracture formulations from the physics and the mechanics communities. Within the formulations stemming from Griffith’s theory, we focus on quasi-static models featuring a tension-compression split, which prevent cracking in compression and interpenetration of the crack faces upon closure, and on the staggered algorithmic implementation due to its proved robustness. In this paper, we establish an appropriate stopping criterion for the staggered scheme. Moreover, we propose and test the so-called hybrid formulation, which leads within a staggered implementation to an incrementally linear problem. This enables a significant reduction of computational cost—about one order of magnitude—with respect to the available (non-linear) models. The conceptual and structural similarities of the hybrid formulation to gradient-enhanced continuum damage mechanics are outlined as well. Several benchmark problems are solved, including one with own experimental verification.

Text stemming is one of the basic preprocessing step for Natural Language Processing applications which is used to transform different word forms into a standard root form. For Arabic script based languages, adequate analysis of text by stemmers is a challenging task due to large number of ambigious structures of the language. In literature, multiple performance evaluation metrics exist for stemmers, each describing the performance from particular aspect. In this work, we review and analyze the text stemming evaluation methods in order to devise criteria for better measurement of stemmer performance. Role of different aspects of stemmer performance measurement like main features, merits and shortcomings are discussed using a resource scarce language i.e. Urdu. Through our experiments we conclude that the current evaluation metrics can only measure an average conflation of words regardless of the correctness of the stem. Moreover, some evaluation metrics favor some type of languages only. None of the existing evaluation metrics can perfectly measure the stemmer performance for all kind of languages. This study will help researchers to evaluate their stemmer using right methods.

We review a selection of methods for performing enhanced sampling in molecular dynamics simulations. We consider methods based on collective variable biasing and on tempering, and offer both historical and contemporary perspectives. In collective-variable biasing, we first discuss methods stemming from thermodynamic integration that use mean force biasing, including the adaptive biasing force algorithm and temperature acceleration. We then turn to methods that use bias potentials, including umbrella sampling and metadynamics. We next consider parallel tempering and replica-exchange methods. We conclude with a brief presentation of some combination methods.

Stemming length and stemming materials are crucial factors in blasting design, which affect the sustainability of mining. This study investigates the influence of stemming length and stemming material on rock fragmentation, stemming recoil, and surface strain response through 15 small-scale model blasting tests. The results indicate that when using clay as a stemming material, increasing the stemming length facilitates rock fragmentation and reduces the stemming recoil area. The strain measurements show that both tensile and compressive strain peaks on the blasting crater surface increase with the growth of stemming length, while the strain peaks on the upper surface decrease. A comparative analysis of different stemming materials reveals that clay performs the best, exhibiting the highest total weight of fragments, blasting crater size, and fragmentation energy utilization. Strain results indicate that clay stemming generates more significant strain peaks and higher strain loading rates on the blasting crater surface, favoring a more concentrated application of explosive energy on the crater surface and improving rock fragmentation. Sand + clay stemming yields fragments more concentrated in medium-sized particles than clay stemming. If the blasting goal is to increase the utilization efficiency of explosive energy and reduce the hazards of stemming recoil, it is recommended to use clay stemming. In addition, if uniform fragmentation is desired (reducing large and fine particles), a combination of sand + clay stemming can be used. These findings have practical implications for optimizing blasting design and engineering applications.

The paper investigates the relationship between organizational ambidexterity and firm performance in knowledge-intensive firms. In particular, using a quantitative methodology involving a structural equation model, the research investigates whether external knowledge sourcing enhances the impact of ambidexterity on firm performance. The results show that organizational ambidexterity in knowledge-intensive firms does not, in fact, have a significant impact on firm performance, but it does have a positive and significant mediating effect considering external knowledge sourcing. The findings are presented along with interesting and significant implications for both theory and practice, largely stemming from the still much neglected relationship between organizational ambidexterity and external knowledge sourcing in the open innovation context.

A bstract We construct renormalizable Standard Model extensions, valid up to the Planck scale, that give a composite Higgs from a new fundamental strong force acting on fermions and scalars. Yukawa interactions of these particles with Standard Model fermions realize the partial compositeness scenario. Under certain assumptions on the dynamics of the scalars, successful models exist because gauge quantum numbers of Standard Model fermions admit a minimal enough ‘square root’. Furthermore, right-handed SM fermions have an SU(2) R -like structure, yielding a custodially-protected composite Higgs. Baryon and lepton numbers arise accidentally. Standard Model fermions acquire mass at tree level, while the Higgs potential and flavor violations are generated by quantum corrections. We further discuss accidental symmetries and other dynamical features stemming from the new strongly interacting scalars. If the same phenomenology can be obtained from models without our elementary scalars, they would reappear as composite states.

Questions Quantifying tree species persistence through recurrent disturbances is of crucial importance for understanding forest dynamics in typhoon‐prone regions. We ask the following: (a) What are the major determinants of dominant tree survival in frequently typhoon‐disturbed forests? (b) Are survival determinants different between small and large trees? Location A subtropical old‐growth forest located in Fushan, Taiwan (24°45′34″N, 121°33′58″E), with frequent typhoon disturbances. Methods Data were from three consecutive censuses of a 25‐ha permanent forest plot that censused trees ≥1 cm in diameter every five years. The survival of three dominant tree species was modeled using generalized additive model and boosted trees with abiotic and biotic predictors. We evaluated model performance using validation data obtained from the two available census intervals. Results Model validations showed that multi‐stemming and tree size enhanced the survival of large and small trees, respectively. For the most dominant species, multi‐stemming had a consistently positive effect on survival irrespective of diameter classes. Abiotic factors and conspecific density had little effect on tree survival. Furthermore, evaluating model performance based on the data used in the model construction (i.e., training data) overestimated the predictive ability of survival models. Conclusions We showed that the survival determinants for the three most dominant species at Fushan changed from tree size for small trees to multi‐stemming for large trees. The results suggest that the dominant species in this frequently typhoon‐disturbed forest have the stature and architectural traits to persist, and thereby maintain their dominance and shape the forest physiognomy. Our approach illustrates how datasets from different census periods can be used in model validation to better assess model performance. In a frequently typhoon‐impacted forest in Taiwan, yet with low mortality, we found that the survival determinants for the dominant species changed from tree size for small trees to multi‐stemming for large trees. The results suggested that the dominant species in this forest had the stature and architectural traits to persist, and thereby maintain their dominance and shape the forest physiognomy. (Photography by Hui‐Yi Yu.)

Stemming is a process of reducing a derivational or inflectional word to its root or stem by stripping all its affixes. It is been used in applications such as information retrieval, machine translation, and text summarization, as their preprocessing step to increase efficiency. Currently, there are a few stemming algorithms which have been developed for languages such as English, Arabic, Turkish, Malay and Amharic. Unfortunately, no algorithm has been used to stem text in Hausa, a Chadic language spoken in West Africa. To address this need, we propose stemming Hausa text using affix-stripping rules and reference lookup. We stemmed Hausa text, using 78 affix stripping rules applied in 4 steps and a reference look-up consisting of 1500 Hausa root words. The over-stemming index, under-stemming index, stemmer weight, word stemmed factor, correctly stemmed words factor and average words conflation factor were calculated to determine the effect of reference look-up on the strength and accuracy of the stemmer. It was observed that reference look-up aided in reducing both over-stemming and under-stemming errors, increased accuracy and has a tendency to reduce the strength of an affix stripping stemmer. The rationality behind the approach used is discussed and directions for future research are identified.