scholarly journals A Mathematical Model of the Production Inventory Problem for Mixing Liquid Considering Preservation Facility

Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3166
Author(s):  
Md Sadikur Rahman ◽  
Subhajit Das ◽  
Amalesh Kumar Manna ◽  
Ali Akbar Shaikh ◽  
Asoke Kumar Bhunia ◽  
...  
Keyword(s):  
Raw Material ◽  
Production Model ◽  
Sensitivity Analyses ◽  
Maximization Problem ◽  
Mixing Process ◽  
Inventory Problem ◽  
Highly Nonlinear ◽  
Production Inventory ◽  
The Impact ◽  
Mixing Problem

The mixing process of liquid products is a crucial activity in the industry of essential commodities like, medicine, pesticide, detergent, and so on. So, the mathematical study of the mixing problem is very much important to formulate a production inventory model of such type of items. In this work, the concept of the mixing problem is studied in the branch of production inventory. Here, a production model of mixed liquids with price-dependent demand and a stock-dependent production rate is formulated under preservation technology. In the formulation, first of all, the mixing process is presented mathematically with the help of simultaneous differential equations. Then, the mixed liquid produced in the mixing process is taken as a raw material of a manufacturing system. Then, all the cost components and average profit of the system are calculated. Now, the objective is to maximize the corresponding profit maximization problem along with the highly nonlinear objective function. Because of this, the mentioned maximization problem is solved numerically using MATHEMATICA software. In order to justify the validity of the model, two numerical examples are worked out. Finally, to show the impact of inventory parameters on the optimal policy, sensitivity analyses are performed and the obtained results are presented graphically.

scholarly journals Bi-level pricing and inventory strategies for perishable products in a competitive supply chain

2021 ◽  
Author(s):  
Naser Rajabi ◽  
Marzieh Mozafari ◽  
Ali Naimi-Sadigh
Keyword(s):  
Supply Chain ◽  
Price Elasticity ◽  
Raw Materials ◽  
Raw Material ◽  
Sensitivity Analyses ◽  
Perishable Product ◽  
Deterioration Rate ◽  
Inventory Decisions ◽  
Joint Pricing ◽  
The Impact

This paper aims to develop a new bi-level game model for joint pricing and inventory decisions in a competitive supply chain consisting of a dominant manufacturer, who produces single perishable product from deteriorating raw materials, and two follower retailers who face nonlinear price-dependent demand and operate under Cournot assumptions. Three levels of warehousing including raw material warehouse, final product warehouse, and retail warehouses with exponential deterioration rates are considered to explore the joint impact of deterioration rate and price elasticity on the equilibrium inventory decisions. A Stackelberg-Nash-Cournot model is developed to seek the equilibrium prices, quantities, and replenishment cycles and is solved through an exact methodology. A numerical example is presented to validate the proposed model and comprehensive sensitivity analyses are carried out to measure the impact of the model’s key parameters including the deterioration rate in the producer’s and the retailers’ warehouses, the retail and competitor price elasticity, and the market scale on the equilibrium.

Optimal and simple algorithms to solve integrated procurement-production-inventory problem without/with shortage

2018 ◽  
Vol 52 (3) ◽  
pp. 755-778 ◽  
Author(s):  
Amir Hossein Nobil ◽  
Leopoldo Eduardo Cárdenas–Barrón ◽  
Erfan Nobil
Keyword(s):  
Raw Materials ◽  
Research Work ◽  
Exact Algorithms ◽  
Optimal Number ◽  
Raw Material ◽  
Convex Programming Problem ◽  
Inventory Problem ◽  
Lot Size ◽  
Total Cost ◽  
Production Inventory

This research work deals with an imperfect production system considering the purchasing of raw materials in order to study the economic production quantity (EPQ). This manufacturing system produces perfect and defective finished products; defectives are considered as scrap. A single product is manufactured from multiple raw materials which are purchased from outside suppliers. In the integrated procurement-production-inventory (IPPI) model, one of the principal decisions, in addition to determining the optimal lot size to produce, is to define the number of optimal orders of each raw material with respect to rate of consumption in the manufacturing of finished product. Two cases are considered: without shortage (first model) and with shortage (backordering, second model). In the first model, the purpose is to determine jointly the optimal lot size to manufacture and the optimal number orders of each raw material in order to minimize the total cost. The second model obtains the optimal number of orders of each raw material, the optimal lot size to manufacture and the optimal shortage level with aim to minimize the total cost. This research also shows that both of the proposed inventory models are a convex programming problem, so exact algorithms to solve these inventory problems are proposed.

Pola Rantai Pasok Industri Kecil Arang Tempurung, Di Kelurahan Muncul, Tangerang Selatan

2018 ◽  
Vol 1 (1) ◽  
pp. 61-66
Author(s):  
Tasya Lianisari ◽  
Amnil Wardiah Hasibuan ◽  
Riri Sintia Subakti ◽  
Sumarni Siregar ◽  
Yeni Mardiah ◽  
...  
Keyword(s):  
Supply Chain ◽  
Bullwhip Effect ◽  
Raw Material ◽  
Chain Process ◽  
Short Supply ◽  
Existing Problems ◽  
Production Inventory ◽  
Supply Chain Process ◽  
Industry Needs ◽  
The Impact

Number of studies stated that a pattern of short supply chain will reduce the impact of the bullwhip effect, because their interpreting data and information systems that are less integrated in each supply chain can be minimized. Therefore, this research seeks to confirm a pattern of supply chain at charcoal home industry di South Tangerang. Results confirmed that there are still constraints on every supply chain process in the production of the industry, as well as still haven't been able to resolve the existing problems in the supply chain of the production process. Policy recommendation for the industry is the industry needs to have warehouse to store and maintain inventory, both raw material inventory and production inventory.

scholarly journals Product Replacement Policy in a Production Inventory Model with Replacement Period-, Stock-, and Price-Dependent Demand

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Subhajit Das ◽  
Amalesh Kumar Manna ◽  
Emad E. Mahmoud ◽  
Kholod M. Abualnaja ◽  
Abdel-Haleem Abdel-Aty ◽  
...  
Keyword(s):  
Nonlinear Function ◽  
Inventory Model ◽  
Replacement Policy ◽  
Sensitivity Analyses ◽  
Model Parameters ◽  
Selling Price ◽  
Proposed Model ◽  
Highly Nonlinear ◽  
Production Inventory ◽  
Market Situation

In the competitive market situation, several companies confer various types of incentives and facilities during product sell to their customers with certain terms and conditions. For the products such as mobile, TV, water purifiers, marshal products, and many more, its corresponding companies offer replacement facility during the guarantee period to enhance the customers’ demand. In this study, we have formulated a production inventory model with considering product’s replacement facility of the failure product within guarantee periods to their customers. This work also leads two vital assumptions: (i) customers’ demand is depending on the replacement period, stock level, and selling price of the product and (ii) the rate of replacement loss of manufacturer’s capital is dependent on the replacement period, and it is a nonlinear function. Since the corresponding optimization problem is highly nonlinear, we have solved it by MATHEMATICA software. The concavity of the centre of interval-valued average profit of the proposed model is shown graphically. In order to justify the validity of the proposed model, a numerical example is considered and solved. Finally, the sensitivity analyses are carried out with respect to the different model parameters.

A Comprehensive Investigation of Ensembles of Gaussian-Based and Gradient-Based Transformed Reliability Analyses: When and How to Use Them

2016 ◽  
Author(s):  
Po Ting Lin ◽  
Wei-Hao Lu ◽  
Shu-Ping Lin
Keyword(s):  
Design Optimization ◽  
Design Space ◽  
Optimization Problems ◽  
Nonlinear Problems ◽  
Kernel Functions ◽  
Sensitivity Analyses ◽  
Normal Space ◽  
Highly Nonlinear ◽  
Standard Normal ◽  
Gradient Based

In the past few years, researchers have begun to investigate the existence of arbitrary uncertainties in the design optimization problems. Most traditional reliability-based design optimization (RBDO) methods transform the design space to the standard normal space for reliability analysis but may not work well when the random variables are arbitrarily distributed. It is because that the transformation to the standard normal space cannot be determined or the distribution type is unknown. The methods of Ensemble of Gaussian-based Reliability Analyses (EoGRA) and Ensemble of Gradient-based Transformed Reliability Analyses (EGTRA) have been developed to estimate the joint probability density function using the ensemble of kernel functions. EoGRA performs a series of Gaussian-based kernel reliability analyses and merged them together to compute the reliability of the design point. EGTRA transforms the design space to the single-variate design space toward the constraint gradient, where the kernel reliability analyses become much less costly. In this paper, a series of comprehensive investigations were performed to study the similarities and differences between EoGRA and EGTRA. The results showed that EGTRA performs accurate and effective reliability analyses for both linear and nonlinear problems. When the constraints are highly nonlinear, EGTRA may have little problem but still can be effective in terms of starting from deterministic optimal points. On the other hands, the sensitivity analyses of EoGRA may be ineffective when the random distribution is completely inside the feasible space or infeasible space. However, EoGRA can find acceptable design points when starting from deterministic optimal points. Moreover, EoGRA is capable of delivering estimated failure probability of each constraint during the optimization processes, which may be convenient for some applications.

Body mass index and risk of all-cause mortality in normotensive and hypertensive adults: The Rural Chinese Cohort Study

2021 ◽  
pp. 1-25
Author(s):  
Qionggui Zhou ◽  
Xuejiao Liu ◽  
Yang Zhao ◽  
Pei Qin ◽  
Yongcheng Ren ◽  
...  
Keyword(s):  
Cohort Study ◽  
Population Based ◽  
Normal Weight ◽  
Sensitivity Analyses ◽  
Hypertension Status ◽  
Moderation Effect ◽  
Increased Risk ◽  
All Cause Mortality ◽  
Chinese Cohort ◽  
The Impact

Abstract Objective: The impact of baseline hypertension status on the BMI–mortality association is still unclear. We aimed to examine the moderation effect of hypertension on the BMI–mortality association using a rural Chinese cohort. Design: In this cohort study, we investigated the incident of mortality according to different BMI categories by hypertension status. Setting: Longitudinal population-based cohort Participants: 17,262 adults ≥18 years were recruited from July to August of 2013 and July to August of 2014 from a rural area in China. Results: During a median 6-year follow-up, we recorded 1109 deaths (610 with and 499 without hypertension). In adjusted models, as compared with BMI 22-24 kg/m2, with BMI ≤18, 18-20, 20-22, 24-26, 26-28, 28-30 and >30 kg/m2, the HRs (95% CI) for mortality in normotensive participants were 1.92 (1.23-3.00), 1.44 (1.01-2.05), 1.14 (0.82-1.58), 0.96 (0.70-1.31), 0.96 (0.65-1.43), 1.32 (0.81-2.14), and 1.32 (0.74-2.35) respectively, and in hypertensive participants were 1.85 (1.08-3.17), 1.67 (1.17-2.39), 1.29 (0.95-1.75), 1.20 (0.91-1.58), 1.10 (0.83-1.46), 1.10 (0.80-1.52), and 0.61 (0.40-0.94) respectively. The risk of mortality was lower in individuals with hypertension with overweight or obesity versus normal weight, especially in older hypertensives (≥60 years old). Sensitivity analyses gave consistent results for both normotensive and hypertensive participants. Conclusions: Low BMI was significantly associated with increased risk of all-cause mortality regardless of hypertension status in rural Chinese adults, but high BMI decreased the mortality risk among individuals with hypertension, especially in older hypertensives.

scholarly journals Impact of public health interventions to curb SARS-CoV-2 spread assessed by an evidence-educated Delphi panel and tailored SEIR model

2021 ◽  
Author(s):  
Bernd Brüggenjürgen ◽  
Hans-Peter Stricker ◽  
Lilian Krist ◽  
Miriam Ortiz ◽  
Thomas Reinhold ◽  
...  
Keyword(s):  
Public Health ◽  
Transmission Rate ◽  
Latency Period ◽  
Policy Decision ◽  
Sensitivity Analyses ◽  
Delphi Panel ◽  
Time Step ◽  
Seir Model ◽  
Health Policy Decision ◽  
The Impact

Abstract Aim To use a Delphi-panel-based assessment of the effectiveness of different non-pharmaceutical interventions (NPI) in order to retrospectively approximate and to prospectively predict the SARS-CoV-2 pandemic progression via a SEIR model (susceptible, exposed, infectious, removed). Methods We applied an evidence-educated Delphi-panel approach to elicit the impact of NPIs on the SARS-CoV-2 transmission rate R0 in Germany. Effectiveness was defined as the product of efficacy and compliance. A discrete, deterministic SEIR model with time step of 1 day, a latency period of 1.8 days, duration of infectiousness of 5 days, and a share of the total population of 15% assumed to be protected by immunity was developed in order to estimate the impact of selected NPI measures on the course of the pandemic. The model was populated with the Delphi-panel results and varied in sensitivity analyses. Results Efficacy and compliance estimates for the three most effective NPIs were as follows: test and isolate 49% (efficacy)/78% (compliance), keeping distance 42%/74%, personal protection masks (cloth masks or other face masks) 33%/79%. Applying all NPI effectiveness estimates to the SEIR model resulted in a valid replication of reported occurrence of the German SARS-CoV-2 pandemic. A combination of four NPIs at consented compliance rates might curb the CoViD-19 pandemic. Conclusion Employing an evidence-educated Delphi-panel approach can support SARS-CoV-2 modelling. Future curbing scenarios require a combination of NPIs. A Delphi-panel-based NPI assessment and modelling might support public health policy decision making by informing sequence and number of needed public health measures.

scholarly journals Functionalization of Enzymatically Treated Apple Pomace from Juice Production by Extrusion Processing

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 485
Author(s):  
Vera Schmid ◽  
Antje Trabert ◽  
Judith (Schäfer) Keller ◽  
Mirko Bunzel ◽  
Heike P. Karbstein ◽  
...  
Keyword(s):  
Water Absorption ◽  
Dietary Fiber ◽  
Water Solubility ◽  
Apple Pomace ◽  
Raw Material ◽  
Food Ingredients ◽  
Insoluble Dietary Fiber ◽  
Extrusion Processing ◽  
The Impact ◽  
Treated Apple

Food by-products can be used as natural and sustainable food ingredients. However, a modification is needed to improve the technofunctional properties according to the specific needs of designated applications. A lab-scale twin-screw extruder was used to process enzymatically treated apple pomace from commercial fruit juice production. To vary the range of the thermomechanical treatment, various screw speeds (200, 600, 1000 min−1), and screw configurations were applied to the raw material. Detailed chemical and functional analyses were performed to develop a comprehensive understanding of the impact of the extrusion processing on apple pomace composition and technofunctional properties as well as structures of individual polymers. Extrusion at moderate thermomechanical conditions increased the water absorption, swelling, and viscosity of the material. An increase in thermomechanical stress resulted in a higher water solubility index, but negatively affected the water absorption index, viscosity, and swelling. Scanning electron microscopy showed an extrusion-processing-related disruption of the cell wall. Dietary fiber analysis revealed an increase of soluble dietary fiber from 12.6 to 17.2 g/100 g dry matter at maximum thermo-mechanical treatment. Dietary fiber polysaccharide analysis demonstrated compositional changes, mainly in the insoluble dietary fiber fraction. In short, pectin polysaccharides seem to be susceptible to thermo-mechanical stress, especially arabinans as neutral side chains of rhamnogalacturonan I.

scholarly journals Online art therapy in elementary schools during COVID-19: results from a randomized cluster pilot and feasibility study and impact on mental health

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Catherine Malboeuf-Hurtubise ◽  
Terra Léger-Goodes ◽  
Geneviève A. Mageau ◽  
Geneviève Taylor ◽  
Catherine M. Herba ◽  
...  
Keyword(s):  
Mental Health ◽  
Elementary School ◽  
Art Therapy ◽  
Feasibility Study ◽  
School Children ◽  
Elementary School Children ◽  
Children’S Mental Health ◽  
Children's Mental Health ◽  
Sensitivity Analyses ◽  
The Impact

Abstract Background Emerging literature on the current COVID-19 crisis suggests that children may experience increased anxiety and depression as a result of the pandemic. To prevent such school and mental health-related problems, there is a timely need to develop preventive strategies and interventions to address potential negative impacts of COVID-19 on children’s mental health, especially in school settings. Results from previous child clinical research indicate that art-based therapies, including mindfulness-based art therapy, have shown promise to increase children’s well-being and reduce psychological distress. Objective The goal of the present pilot and feasibility study was to compare the impact of an emotion-based directed drawing intervention and a mandala drawing intervention, on mental health in elementary school children (N = 22), in the context of the COVID-19 pandemic. Both interventions were group-based and delivered online and remotely. A pilot study using a randomized cluster design was implemented to evaluate and compare both interventions in relation to child anxiety, depression, inattention and hyperactivity symptoms. Results Analyses of covariance revealed a significant effect of the type of drawing intervention on levels of inattention, after controlling for baseline levels. Participants in the emotion-based directed drawing group showed lower inattention scores at post-test, when compared to participants in the mandala group. Post-hoc sensitivity analyses showed significant decreases in pre-to-post scores for levels of hyperactivity for the complete sample. Conclusion Overall, results from this pilot and feasibility study showed that both an emotion-based directed drawing intervention and a mandala drawing intervention may be beneficial to improve mental health in elementary school children, in the context of the current COVID-19 pandemic. From a feasibility standpoint, results indicate that the implementation of both interventions online and remotely, through a videoconference platform, is feasible and adequate in school-based settings. Further work incorporating larger sample sizes, longitudinal data and ensuring sufficient statistical power is warranted to evaluate the long-term impact of both interventions on children’s mental health.

Gastrostomy Tubes Placed in Children With Neurologic Impairment: Associated Morbidity and Mortality

2021 ◽  
pp. 088307382110001
Author(s):  
Jody L. Lin ◽  
Joseph Rigdon ◽  
Keith Van Haren ◽  
MyMy Buu ◽  
Olga Saynina ◽  
...  
Keyword(s):  
Severe Pneumonia ◽  
Sensitivity Analyses ◽  
Tube Placement ◽  
Composite Outcome ◽  
Eligibility Criteria ◽  
Risk Of Death ◽  
Cox Proportional Hazard ◽  
Neurologic Impairment ◽  
Increased Risk ◽  
The Impact

Background: Gastrostomy tube (G-tube) placement for children with neurologic impairment with dysphagia has been suggested for pneumonia prevention. However, prior studies demonstrated an association between G-tube placement and increased risk of pneumonia. We evaluate the association between timing of G-tube placement and death or severe pneumonia in children with neurologic impairment. Methods: We included all children enrolled in California Children’s Services between July 1, 2009, and June 30, 2014, with neurologic impairment and 1 pneumonia hospitalization. Prior to analysis, children with new G-tubes and those without were 1:2 propensity score matched on sociodemographics, medical complexity, and severity of index hospitalization. We used a time-varying Cox proportional hazard model for subsequent death or composite outcome of death or severe pneumonia to compare those with new G-tubes vs those without, adjusting for covariates described above. Results: A total of 2490 children met eligibility criteria, of whom 219 (9%) died and 789 (32%) had severe pneumonia. Compared to children without G-tubes, children with new G-tubes had decreased risk of death (hazard ratio [HR] 0.47, 95% confidence interval [CI] 0.39-0.55) but increased risk of the composite outcome (HR 1.21, CI 1.14-1.27). Sensitivity analyses using varied time criteria for definitions of G-tube and outcome found that more recent G-tube placement had greater associated risk reduction for death but increased risk of severe pneumonia. Conclusion: Recent G-tube placement is associated with reduced risk of death but increased risk of severe pneumonia. Decisions to place G-tubes for pulmonary indications in children with neurologic impairment should weigh the impact of severe pneumonia on quality of life.

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