Two Weighted Fuzzy Goal Programming Methods to Solve Multiobjective Goal Programming Problem

We propose two new methods to find the solution of fuzzy goal programming (FGP) problem by weighting method. Here, the relative weights represent the relative importance of the objective functions. The proposed methods involve one additional goal constraint by introducing only underdeviation variables to the fuzzy operator λ (resp., 1-λ), which is more efficient than some well-known existing methods such as those proposed by Zimmermann, Hannan, Tiwari, and Mohamed. Mohamed proposed that every fuzzy linear program has an equivalent weighted linear goal program where the weights are restricted as the reciprocals of the admissible violation constants. But the above proposition of Mohamed is not always true. Furthermore, the proposed methods are easy to apply in real-life situations which give better solution in the sense that the objective values are sufficiently closer to their aspiration levels. Finally, for illustration, two real examples are used to demonstrate the correctness and usefulness of the proposed methods

Stage structured prey-predator model incorporating mortal peril consequential to inefficiency and habitat complexity in juvenile hunting

Dynamic exploration for a predator-prey bio-system of two species with ratio-dependent functional response is carried out, where the capability to predate in both the stages of the predator, the juvenile and the matured, is taken into account. But, only the matured predators are inferred to be efficient in killing the prey without any negative repercussions. The mortality risks for the juvenile predators are attributable to the inefficiency rate of juveniles coupled with habitat complexity which is either in the form of anti-predator behavior of the prey taken with the aid of their habitat or in the form of a territorial generalist mesopredator. So as to avoid extinction of either of the species and to preserve the food chain of the ecological system, the results pertaining to the existence and stability of all the equilibrium points of the bio-system along with permanence, transcritical and Hopf bifurcation has been thoroughly studied. Corroboration of the results along with the dependence of the biosystem on some crucial parameters is done through numerical simulation. It is found that juvenile predators' inefficiency relative to the resistance confronted, plays a crucial role to control each species density of the ecosystem, as an intriguing limit cycle between the trivial and axial equilibriums of the proposed system along with the co-existing periodic point, because of some ineffeciency parametric value of the juvenile predator has been witnessed

A discrete-time dynamical model of prey and stage-structured predator with juvenile hunting incorporating negative effects of prey refuge

This paper examines a discrete predator-prey model that incorporates prey refuge and its detrimental impact on the growth of the prey population. Age structure is taken into account for predator species. Furthermore, juvenile hunting as well as prey counter-attack are also considered. This paper provides a comprehensive analysis of the existence and stability conditions pertaining to all possible fixed points. The analytical and numerical investigation into the occurrence of different bifurcations, such as the Neimark-Sacker bifurcation and period-doubling bifurcation, in relation to various parameters is discussed. The impact of the parameters reflecting prey growth and prey refuge is thoroughly addressed. Numerous numerical simulations are presented in order to validate the theoretical findings

Predator-prey dynamics pertaining to structuralizing predator species into three stages coupled with maturation delay owing to juvenile hunting

The predator-prey dynamic appertaining to two species is explored, wherein the predator species is structured into different stages. As evidenced from natural documentation, the immature predators possess the potential to predate albeit not as competently as the adults. Nevertheless, this potentiality is not acquired immediately after their incipience of life, hence, the immature stage is branched off into the infant stage, the stage with extensive reliance on the adults, and the juvenile stage, the stage with the potential to predate but not to procreate. In this paper, this inaugural concept is coupled with injuries in the juvenile stage as the repercussion of their incompetency in predating, thereby ensuing a delay in their maturation. With the incentive to investigate the ascendancy of these refinements over the whole system, stability analyses along with various bifurcation analyses around the equilibrium points of the system are corroborated. In addition to Hopf, transcritical, and saddle node bifurcations, the existence of Bogdanov-Takens point, cusp point, Bautin bifurcation point, bloom phenomenon, twice occurring Hopf bifurcation, and bi-stability phenomenon make the paper appreciably more rich and efficacious

Two predators one prey model that integrates the effect of supplementary food resources due to one predator's kleptoparasitism under the possibility of retribution by the other predator

In ecology, foraging requires animals to expend energy in order to obtain resources. The cost of foraging can be reduced through kleptoparasitism, the theft of a resource that another individual has expended effort to acquire. Thus, kleptoparasitism is one of the most significant feeding techniques in ecology. In this study, we investigate a two predator one prey paradigm in which one predator acts as a kleptoparasite and the other as a host. This research considers the post-kleptoparasitism scenario, which has received little attention in the literature. Parametric requirements for the existence as well as local and global stability of biologically viable equilibria have been proposed. The occurrences of various one parametric bifurcations, such as saddle-node bifurcation, transcritical bifurcation, and Hopf bifurcation, as well as two parametric bifurcations, such as Bautin bifurcation, are explored in depth. Relatively low growth rate of first predator induces a subcritical Hopf bifurcation although a supercritical Hopf bifurcation occurs at relatively high growth rate of first predator making coexistence of all three species possible. Some numerical simulations have been provided for the purpose of verifying our theoretical conclusions

Role of Reactive Oxygen Species in Mercapto-Methylimidazole-Induced Gastric Acid Secretion and Stress-Induced Gastric Ulceration

The objective of the present study is to delineate the role of reactive oxygen species in drug-induced gastric hyperacidity and stress-induced gastric ulceration. We reported earlier that mercaptomethylimidazole (MMI), an antithyroid drug, induces gastric acid (HCl) secretion partially through H2receptor activation of the parietal cell by histamine release and partially through an intracellular mechanism. While studying the latter, MMI-induced acid secretion was found to correlate well with the inactivation of the peroxidase, an important H2O2metabolizing enzyme of the mucosa. MMI activates the isolated parietal cell for acid secretion, which is sensitive to omeprazole. Peroxidase and catalase activity of the isolated cell is also irreversibly inactivated by MMI. It thus creates a favourable condition for endogenous accumulation of H2O2. Acid secretion by gastric gland preparation or isolated gastric mucosa is stimulated by exogenous H2O2, which is inhibited by omeprazole. Studies indicate that H2O2inactivates the prostaglandin synthetase and removes the inhibitory influence of prostaglandin on acid secretion. MMI thus stimulates acid secretion not only through H2, receptor activation but also through the stimulation of the parietal cell by intracellular generation of H2O2following inactivation of the peroxidase-catalase system. Among the various factors responsible for gastric ulceration, stress was found to cause severe haemorrhagic lesions mainly through oxidative damage of the mucosa as indicated by increased lipid peroxidation, increased protein carbonyl content, and decreased glutathione level. The severity of ulcer correlates well with the time-dependent induction of superoxide dismutase and inactivation of peroxidase, a condition favourable for accumulation of endogenous H2O2. Desferrioxamine prevents stress ulcer, indicating involvement of transition metal ion in the process. Studies indicate that severity of stress ulcer is dependent on the concurrent generation of hydroxyl radical (•OH) formed through metal-catalysed Haber-Weiss reaction between O2-and H2O2

An Exploratory Study to Find Motives Behind Cross-platform Forks from Software Heritage Dataset

The fork-based development mechanism provides the flexibility and the unified processes for software teams to collaborate easily in a distributed setting without too much coordination overhead.Currently, multiple social coding platforms support fork-based development, such as GitHub, GitLab, and Bitbucket. Although these different platforms virtually share the same features, they have different emphasis. As GitHub is the most popular platform and the corresponding data is publicly available, most of the current studies are focusing on GitHub hosted projects. However, we observed anecdote evidences that people are confused about choosing among these platforms, and some projects are migrating from one platform to another, and the reasons behind these activities remain unknown.With the advances of Software Heritage Graph Dataset (SWHGD),we have the opportunity to investigate the forking activities across platforms. In this paper, we conduct an exploratory study on 10popular open-source projects to identify cross-platform forks and investigate the motivation behind. Preliminary result shows that cross-platform forks do exist. For the 10 subject systems in this study, we found 81,357 forks in total among which 179 forks are on GitLab. Based on our qualitative analysis, we found that most of the cross-platform forks that we identified are mirrors of the repositories on another platform, but we still find cases that were created due to preference of using certain functionalities (e.g. Continuous Integration (CI)) supported by different platforms. This study lays the foundation of future research directions, such as understanding the differences between platforms and supporting cross-platform collaboration.Comment: Accepted at 17th International Conference on Mining Software Repositories, October 5--6, 2020, Seoul, Republic of Kore

Numerical Analysis of Turbulent Fluid Flow and Heat Transfer in a Rectangular Elbow

The numerical analysis of turbulent fluid flow and heat transfer through a rectangular elbow has been done by model with standard wall function. Different inlet uniform velocities of 5m/s, 10m/s, 15 m/s, 20 m/s and 25 m/s corresponding to Reynolds numbers of Re1= 4.09× 104, Re2= 8.17 × 104, Re3= 12.25× 104, Re4= 16.34× 104 and Re5 =20.43 × 104 have been considered for the numerical experimentations. The fluid considered was incompressible, Newtonian non-reacting and the flow was fully turbulent. The heat transfer analysis has been carried out by considering the fluid having at a higher temperature while the wall kept at lower temperature. A detailed study of the turbulent fluid flow shows that presence of recirculation is inevitable at every corner position or at every bend indicating presence of secondary flow incurring energy losses. The velocity distributions at different stations along the downstream path of the elbow have been plotted. The presence of this adverse pressure gradient is confirmed by the reverse velocity or the negative velocity in the vicinity of the vertical wall. In the upper corner there is a vortex extending from the upper wall of the upper limb almost touching the end point of the left wall of the vertical portion of the elbow. The heat transfer also shows the similar tendency as the fluid flow field influences the convective heat transfer process. The detail temperature distributions across any cross section basically explain the dependence of the convective heat transfer on the fluid flow field