196 research outputs found
Introducing a new formulation for the warehouse inventory management systems : with two stochastic demand patterns
This paper presents a new formulation for warehouse inventory management in a stochastic situation. The primary source of this formulation is derived from FP model, which has been proposed by Fletcher and Ponnambalam for reservoir management. The new proposed mathematical model is based on the first and the second moments of storage as a stochastic variable. Using this model, the expected value of storage, the variance of storage, and the optimal ordering policies are determined. Moreover, the probability of within containment, surplus, and shortage are computable without adding any new variables. To validate the optimization model, a Monte Carlo simulation is used. Furthermore, to evaluate the performance of the optimal FP policy, It is compared to (s*,S*) policy, as a very popular policy used in the literature, in terms of the expected total annual cost and the service level. It is also demonstrated that the FP policy has a superior performances than (s*,S*) policy
Computationally efficient calibration of WATCLASS Hydrologic models using surrogate optimization
International audienceIn this approach, exploration of the cost function space was performed with an inexpensive surrogate function, not the expensive original function. The Design and Analysis of Computer Experiments(DACE) surrogate function, which is one type of approximate models, which takes correlation function for error was employed. The results for Monte Carlo Sampling, Latin Hypercube Sampling and Design and Analysis of Computer Experiments(DACE) approximate model have been compared. The results show that DACE model has a good potential for predicting the trend of simulation results. The case study of this document was WATCLASS hydrologic model calibration on Smokey-River watershed
The LOX-1 Scavenger Receptor and Its Implications in the Treatment of Vascular Disease
Cardiovascular disease is the leading cause of death. The disease is due to atherosclerosis which is characterized by lipid and fat accumulation in arterial blood vessel walls. A key causative event is the accumulation of oxidised low density lipoprotein particles within vascular cells, and this is mediated by scavenger receptors. One such molecule is the LOX-1 scavenger receptor that is expressed on endothelial, vascular smooth muscle, and lymphoid cells including macrophages. LOX-1 interaction with OxLDL particles stimulates atherosclerosis. LOX-1 mediates OxLDL endocytosis via a clathrin-independent internalization pathway. Transgenic animal model studies show that LOX-1 plays a significant role in atherosclerotic plaque initiation and progression. Administration of LOX-1 antibodies in cellular and animal models suggest that such intervention inhibits atherosclerosis. Antiatherogenic strategies that target LOX-1 function using gene therapy or small molecule inhibitors would be new ways to address the increasing incidence of vascular disease in many countries
Rheological Behaviour of Ceramic Inks for Direct Ceramic Inkjet Printing
In this paper, studies were made on the preparation of ceramic inks with: (i) alumina powderin ethyl alcohol and (ii) zirconia powder in ethyl alcohol at different volume fractions of ceramic.Different amounts (0.75-3.00 vol %) of an organic dispersant (oleic acid) were added to ceramicink containing 5 per cent of ceramic by volume in ethyl alcohol. The viscosities of the suspensionswere determined with Brookefield viscometer (model: DV-E), which is suitable for measuringthe viscosities of suspensions accurately. These inks were deposited on a substrate to see theirspread. The sediment packing densities ( m) of the resulting suspensions were calculated usingtheoretical models which can be related to the density that can be achieved in the final product.The highest sediment packing density was arrived at low viscosity values of the ink and occurredwhen 1 per cent of dispersant by volume was used for 5 per cent alumina content. For 5 percent zirconia content, 2 per cent of dispersant by volume gave a similar result. Experimentswere also conducted to find the value of m for different solid loadings (5-25 vol %) of ceramicwith 1 per cent dispersant. It was observed that the sediment packing density and the apparentviscosities were increasing when solid loading concentrations were increased for both aluminaand zirconia-based inks. The optimum value of m and viscosity have been determined from thisstudy. The results of this preliminary study will be useful for further investigations on therheological behaviour of ceramic inks for direct ceramic inkjet printing
Simulation of Droplet Formation, Ejection, Spread, and Preliminary Designof Nozzle for Direct Ceramic Inkjet Printing
Recent advances in drop-on-demand (DOD)-type inkjet printing techniques have increasedresearch activities in the area of direct ceramic inkjet printing. In an attempt to develop a ceramicinkjet printer for the manufacture of ceramic components with their sizes in micro scale, theformation of ceramic ink droplet (ethyl alcohol loaded with different volume fractions of aluminaparticles) and its spread from a reservoir using piezoelectric actuation are simulated. The propertiesof the ceramic ink are taken from the data reported in literature. The simulations were performedwith computational fluid dynamics software (CFD-ACE+), CFDRC. This study gives details ofthe interaction among different physical phenomena that contribute to the droplet formation andejection process. The results from this study are being used for a preliminary design of nozzleand for the preparation of ceramic inks to achieve the desired droplet characteristics
A Study on Urban Water Reuse Management Modeling
Water reuse is being recognized as a sustainable urban water management strategy and is becoming increasingly attractive in urban water resources management. This paper focuses on urban water reuse planning and management in the context of sustainable development, and introduces a state of the art urban water reuse management model which utilizes a network flow optimization model and various stochastic programming methods. The objective of the model is to minimize the overall cost of the system subject to technological, societal and environmental constraints, therefore the optimum allocation of urban water resources can be obtained. Uncertainty issues associated with water demand and treatment quality are modeled by introducing stochastic programming methods, namely, twostage stochastic recourse programming and chance-constraint programming. An application is presented in order to demonstrate the modeling process and to analyze the impact of uncertainties. This research is important in aiding the achievement in sustainable urban water resource management practices
Analyze the factors influencing human-robot interaction using MCDM method
Robots play a key role in medical equipment manufacturing industry by safeguarding human workers from hazardous environment and risky jobs. Human robot interaction (HRI) is one of the robotic features that are enhanced in industrial robots. They mimic human behavior while arriving at a decision, contributing to the proficiency of the product. Tasks involving human cognitive skills and flexibility in the workers are combined with robots to obtain high-level accuracy, repeatability, and speed. Further, more challenges are to be met for achieving an effective human-robot interaction. In this paper, risk factors affecting the interaction between both robot and humans are discussed, and a contextual case is performed in a top south Indian medical equipment manufacturing industry. Industrial experts' inputs and relevant literature are considered to recognize the risk factors. Multi-Criteria decision-making method (MCDM) like DEMATEL (Decision Making Trial and Evaluation Laboratory) is used to analyze the risk factors influencing HRI in the assembly section. The paper's findings show that automation level and reliability of the robot are the most influential factor in the assembly section and need more attention to control and reduce the risk factor for the effective assembly
Plasmin Inhibitor in Health and Diabetes: Role of the Protein as a Therapeutic Target
The vascular obstructive thrombus is composed of a mesh of fibrin fibers with blood cells trapped in these networks. Enhanced fibrin clot formation and/or suppression of fibrinolysis are associated with an increased risk of vascular occlusive events. Inhibitors of coagulation factors and activators of plasminogen have been clinically used to limit fibrin network formation and enhance lysis. While these agents are effective at reducing vascular occlusion, they carry a significant risk of bleeding complications. Fibrin clot lysis, essential for normal hemostasis, is controlled by several factors including the incorporation of antifibrinolytic proteins into the clot. Plasmin inhibitor (PI), a key antifibrinolytic protein, is cross-linked into fibrin networks with higher concentrations of PI documented in fibrin clots and plasma from high vascular risk individuals. This review is focused on exploring PI as a target for the prevention and treatment of vascular occlusive disease. We first discuss the relationship between the PI structure and antifibrinolytic activity, followed by describing the function of the protein in normal physiology and its role in pathological vascular thrombosis. Subsequently, we describe in detail the potential use of PI as a therapeutic target, including the array of methods employed for the modulation of protein activity. Effective and safe inhibition of PI may prove to be an alternative and specific way to reduce vascular thrombotic events while keeping bleeding risk to a minimum
Modelling pollutants transport scenarios based on the X-Press Pearl disaster
The MV X-Press Pearl accident near Sri Lanka in May 2021 released several pollutants into the ocean, including 1843.3 t of urea, raising concerns about the impact on the region. This study uses a coupled ocean (NEMO)–biogeochemistry (ERSEM) model to simulate urea dispersion under various scenarios. While it doesn't directly reflect the real accident, it provides insights into the potential impact of similar chemical spills. By adjusting tracer release rates and timing, we assessed their impact on the distribution of the chemical plume. Findings show slower release rates prolong higher urea concentrations, potentially causing phytoplankton blooms, while monsoon conditions significantly affect dispersal patterns. Due to a lack of publicly available urea observations, we used particle tracking experiments validated with data on plastic nurdle beaching. This research shows how a simpler, affordable scenario approach could inform the management of chemical spills without a fully developed operational oceanographic system
In silico design and biological evaluation of a dual specificity kinase inhibitor targeting cell cycle progression and angiogenesis
Methodology: We have utilized a rational in silico-based approach to demonstrate the design and study of a novel compound that acts as a dual inhibitor of vascular endothelial growth factor receptor 2 (VEGFR2) and cyclin-dependent kinase 1 (CDK1). This compound acts by simultaneously inhibiting pro-Angiogenic signal transduction and cell cycle progression in primary endothelial cells. JK-31 displays potent in vitro activity against recombinant VEGFR2 and CDK1/cyclin B proteins comparable to previously characterized inhibitors. Dual inhibition of the vascular endothelial growth factor A (VEGF-A)-mediated signaling response and CDK1-mediated mitotic entry elicits anti-Angiogenic activity both in an endothelial-fibroblast co-culture model and a murine ex vivo model of angiogenesis
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