scholarly journals Optimizing Long-Lasting Insecticidal Nets Campaign in Ivory Coast

Logistics ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 18
Author(s):  
Irineu de Brito ◽  
Silvia Uneddu ◽  
Emma Maspero ◽  
Paulo Gonçalves
Keyword(s):  
Network Flow ◽  
Ivory Coast ◽  
Optimal Transport ◽  
Cost Effective ◽  
Mixed Integer ◽  
Efficient Manner ◽  
Humanitarian Organizations ◽  
Mosquito Nets ◽  
Long Lasting Insecticidal Nets ◽  
Health Districts

This research supports the United Nations Children’s Fund’s (UNICEF) conceptualization, planning and implementation of a campaign for distribution of more than 12 million mosquito nets in Ivory Coast. Procured from four different suppliers in Asia, the nets were transported to the two ports in Ivory Coast before being pre-positioned at 71 Health Districts across the country, a mixed integer network flow model identifies optimal transport options. The process of modeling and the model developed in this paper brought a significant understanding of the problem and, consequently, a reduction in the overall procurement and logistics costs. The implications of using mathematical modeling by practitioners as a tool which contributes to solve humanitarian logistics problems are significant. Mathematical models, like linear programming, can greatly support overall decision-making within humanitarian organizations by helping to ensure that limited resources are used in the most cost-effective and efficient manner. However, it is important to ensure consultations with and involvement by on the ground practitioners to ensure developed solutions assessed to fit the operating context before being implemented.

Simultaneous Selective Disassembly and End-of-Life Decision Making for Multiple Products That Share Disassembly Operations

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Sara Behdad ◽  
Minjung Kwak ◽  
Harrison Kim ◽  
Deborah Thurston
Keyword(s):  
End Of Life ◽  
Cell Phone ◽  
Value Added ◽  
Cost Effective ◽  
Mixed Integer ◽  
Efficient Manner ◽  
Multiple Products ◽  
Take Back ◽  
Protection Legislation ◽  
Selective Disassembly

Environmental protection legislation, consumer interest in “green” products, a trend toward corporate responsibility and recognition of the potential profitability of salvaging operations, has resulted in increased interest in product take back. However, the cost effectiveness of product take-back operations is hampered by many factors, including the high cost of disassembly and a widely varying feedstock of dissimilar products. Two types of decisions must be made, how to carry out the disassembly process in the most efficient manner to “mine” the value-added that is still embedded in the product, and then how to best utilize that value-added once it is recovered. This paper presents a method for making those decisions. The concept of a transition matrix is integrated with mixed integer linear programming to determine the extent to which products should be disassembled and simultaneously determine the optimal end-of-life (EOL) strategy for each resultant component or subassembly. The main contribution of this paper is the simultaneous consideration of selective disassembly, multiple products, and the value added that remains in each component or subassembly. Shared disassembly operations and capacity limits are considered. An example using two cell phone products illustrates application of the model. The obtained results demonstrate the most economical level of disassembly for each cell phone and the best EOL options for each resultant module. In addition, the cell phone example shows that sharing disassembly operations between different products makes disassembly more cost effective compared with the case in which each product is disassembled separately.

scholarly journals Cost-effectiveness of two long-lasting insecticidal nets delivery models in mass campaign in rural Mozambique

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Jorge A. H. Arroz ◽  
Baltazar Candrinho ◽  
Chandana Mendis ◽  
Melanie Lopez ◽  
Maria do Rosário O. Martins
Keyword(s):  
Cost Effectiveness ◽  
Cost Effective ◽  
Universal Coverage ◽  
Cost Effectiveness Ratio ◽  
Net Benefit ◽  
Incremental Net Benefit ◽  
The Cost ◽  
And Control ◽  
Delivery Models ◽  
Long Lasting Insecticidal Nets

Abstract Objective The aim is to compare the cost-effectiveness of two long-lasting insecticidal nets (LLINs) delivery models (standard vs. new) in universal coverage (UC) campaigns in rural Mozambique. Results The total financial cost of delivering LLINs was US$ 231,237.30 and US$ 174,790.14 in the intervention (302,648 LLINs were delivered) and control districts (219,613 LLINs were delivered), respectively. The average cost-effectiveness ratio (ACER) per LLIN delivered and ACER per household (HH) achieving UC was lower in the intervention districts. The incremental cost-effectiveness ratio (ICER) per LLIN and ICER per HH reaching UC were US$ 0.68 and US$ 2.24, respectively. Both incremental net benefit (for delivered LLIN and for HHs reaching UC) were positive (intervention deemed cost-effective). Overall, the newer delivery model was the more cost-effective intervention. However, the long-term sustainability of either delivery models is far from guaranteed in Mozambique’s current economic context.

scholarly journals From Linear Programming Model to Mixed Integer Linear Programming Model for the Simultaneous Optimisation of Water Allocation and Reservoir Location in River Systems

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 594 ◽  
Author(s):  
Jaime Veintimilla-Reyes ◽  
Annelies De Meyer ◽  
Dirk Cattrysse ◽  
Jos Van Orshoven
Keyword(s):  
Linear Programming ◽  
Network Flow ◽  
Water Allocation ◽  
Programming Model ◽  
Water Levels ◽  
Linear Programming Model ◽  
Mixed Integer ◽  
Network Configuration ◽  
Spatially Distributed ◽  
Lp Model

The allocation of water flowing through a river-with-reservoirs system to optimally meet spatially distributed and temporally variable demands can be conceived as a Network Flow Optimisation (NFO) problem and addressed by Linear Programming (LP). In this paper we present an extension of the strategic NFO-LP model to simultaneously optimise the allocation of water and the location of one or more reservoirs. The applicability of the MILP model has been illustrated by applying it to a hypothetical river network configuration consisting of seven candidate reservoir nodes and seven demand nodes, and by comparing the outcome (water levels in selected reservoir, penalties) with the values obtained by the original LP-model for the same network with six reservoirs present.

scholarly journals Design parameters influencing the operation of a CHP plant within a micro-grid: application of the ANOVA test

2020 ◽  
Vol 197 ◽  
pp. 01002
Author(s):  
Alberto Fichera ◽  
Arturo Pagano ◽  
Rosaria Volpe
Keyword(s):  
Power Systems ◽  
Programming Model ◽  
Cost Effective ◽  
Combined Heat And Power ◽  
Mixed Integer ◽  
Design Parameters ◽  
Statistical Tool ◽  
Cogeneration System ◽  
Micro Grid ◽  
Cost Parameters

Combined heat and power systems are widely recognized as a cost-effective solution for the achievement of sustainable and energy efficiency goals. During the last decade, cogeneration systems have been extensively studied from both the technological and operational viewpoints. However, the operation of a cogeneration system is a topic still worth of investigation. In fact, along with the determination of the optimal configurations of the combined heat and power systems, it is likewise fundamental to increase the awareness on the design and cost parameters affecting the operation of cogeneration systems, especially if considering the micro-grid in which they are inserted. In this direction, this paper proposed a mixed integer linear programming model with the objective of minimizing the total operational costs of the micro-grid. Different scenarios include the satisfaction of the cooling demands of the micro-grid as well as the opportuneness to include a heat storage. The influence of the main design and cost parameters on the operation of the micro-grid has been assessed by adopting the statistical tool ANOVA (Analysis Of Variance). The model and the experimental application of the ANOVA have been applied to a micro-grid serving a hospital located in the South of Italy.

scholarly journals Highway Passenger Transport Based Express Parcel Service Network Design: Model and Algorithm

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Yuan Jiang ◽  
Baofeng Sun ◽  
Gendao Li ◽  
Zhibin Lin ◽  
Changxu Zheng ◽  
...  
Keyword(s):  
Network Design ◽  
Network Flow ◽  
Programming Model ◽  
Real Data ◽  
Path Selection ◽  
Network Design Problem ◽  
Mixed Integer ◽  
Passenger Transport ◽  
Service Network ◽  
Time Space

Highway passenger transport based express parcel service (HPTB-EPS) is an emerging business that uses unutilised room of coach trunk to ship parcels between major cities. While it is reaping more and more express market, the managers are facing difficult decisions to design the service network. This paper investigates the HPTB-EPS network design problem and analyses the time-space characteristics of such network. A mixed-integer programming model is formulated integrating the service decision, frequency, and network flow distribution. To solve the model, a decomposition-based heuristic algorithm is designed by decomposing the problem as three steps: construction of service network, service path selection, and distribution of network flow. Numerical experiment using real data from our partner company demonstrates the effectiveness of our model and algorithm. We found that our solution could reduce the total cost by up to 16.3% compared to the carrier’s solution. The sensitivity analysis demonstrates the robustness and flexibility of the solutions of the model.

scholarly journals Dynamic Gaming Case of the R-Interdiction Median Problem with Fortification and an MILP-Based Solution Approach

2020 ◽  
Vol 12 (2) ◽  
pp. 581 ◽  
Author(s):  
Yiyong Xiao ◽  
Pei Yang ◽  
Siyue Zhang ◽  
Shenghan Zhou ◽  
Wenbing Chang ◽  
...  
Keyword(s):  
Large Scale ◽  
Dynamic Equilibrium ◽  
Cost Effective ◽  
Mixed Integer ◽  
Single Pair ◽  
Median Problem ◽  
Solution Approach ◽  
Maximum Loss ◽  
Large Scale Problems ◽  
Objective Model

This paper studies the cyclic dynamic gaming case of the r-interdiction median problem with fortification (CDGC-RIMF), which is important for strengthening a facility’s reliability and invulnerability under various possible attacks. We formulated the CDGC-RIMF as a bi-objective mixed-integer linear programming (MILP) model with two opposing goals to minimize/maximize the loss from both the designer (leader) and attacker (follower) sides. The first goal was to identify the most cost-effective plan to build and fortify the facility considering minimum loss, whereas the attacker followed the designer to seek the most destructive way of attacking to cause maximum loss. We found that the two sides could not reach a static equilibrium with a single pair of confrontational plans in an ordinary case, but were able to reach a dynamically cyclic equilibrium when the plan involved multiple pairs. The proposed bi-objective model aimed to discover the optimal cyclic plans for both sides to reach a dynamic equilibrium. To solve this problem, we first started from the designer’s side with a design and fortification plan, and then the attacker was able to generate their worst attack plan based on that design. After that, the designer changed their plan again based on the attacker’s plan in order to minimize loss, and the attacker correspondingly modified their plan to achieve maximum loss. This game looped until, finally, a cyclic equilibrium was reached. This equilibrium was deemed to be optimal for both sides because there was always more loss for either side if they left the equilibrium first. This game falls into the subgame of a perfect Nash equilibrium—a kind of complete game. The proposed bi-objective model was directly solved by the CPLEX solver to achieve optimal solutions for small-sized problems and near-optimal feasible solutions for larger-sized problems. Furthermore, for large-scale problems, we developed a heuristic algorithm that implemented dynamic iterative partial optimization alongside MILP (DIPO-MILP), which showed better performance compared with the CPLEX solver when solving large-scale problems.

MULTI-TONE WAVEFORM MEASUREMENT SYSTEM ENABLING CHARACTERIZATION OF MICROWAVE DEVICES

2014 ◽  
Vol 23 (10) ◽  
pp. 1450141
Author(s):  
MUHAMMAD AKMAL CHAUDHARY ◽  
JONATHAN LEES ◽  
JOHANNES BENEDIKT ◽  
PAUL TASKER
Keyword(s):  
Measurement System ◽  
Measurement Data ◽  
Quality Measurement ◽  
Cost Effective ◽  
Operating Conditions ◽  
Efficient Manner ◽  
Vector Error Correction ◽  
Sampling Oscilloscope ◽  
Rf Components ◽  
Vector Error

This paper presents a fully automated time domain, waveform measurement system, capable of measuring multi-tone waveforms up to a frequency of 14 GHz. Multi-tone waveform measurement capabilities will prove useful in enhancing the understanding of the response of devices under realistic operating conditions, and allow for detailed investigation into device problems leading to memory effects. The system, which is based around a standard sampling oscilloscope, is capable of measuring all four traveling waves simultaneously. It is a cost effective solution, capable of capturing high quality measurement data, it consists of two test sets one to measure RF components of the signal and one to measure IF components, which are then recombined before being measured by the sampling oscilloscope. Vector error correction is applied to the measured data to fully calibrate the system to the device plane, ensuring any dispersion in the connecting hardware is removed. A multi-tone waveform sampling method is employed, ensuring the waveforms are captured in the most efficient manner. Device results are presented showing the multi-tone voltage and current waveforms at the device plane. Some useful applications of the system are demonstrated and explained.

scholarly journals PO 7167 IMPROVING USE OF LONG-LASTING INSECTICIDAL NETS IN KAYANGE COMMUNITY OF NORTH-WESTERN BURUNDI: A QUALITY IMPROVEMENT STUDY

2019 ◽  
Vol 4 (Suppl 3) ◽  
pp. A20.1-A20
Author(s):  
Desire Habonimana ◽  
Gabriel Ndayisaba ◽  
Gideon Nimako
Keyword(s):  
Quality Improvement ◽  
General Population ◽  
Pregnant Women ◽  
Cost Effective ◽  
Universal Coverage ◽  
Malaria Prevention ◽  
Quality Improvement Intervention ◽  
Long Lasting Insecticidal Nets ◽  
North Western ◽  
Children Under 5

BackgroundThe use of long-lasting insecticidal nets (LLINs) for malaria prevention is a cost-effective intervention. WHO recommends universal coverage and use of LLINs. In lower- and middle-income countries, LLINs are provided free of charge but are either not used or misused. Our study sought to improve LLIN use in Kayange community of north-western Burundi by using a model for improvement (MFI).MethodsA one-group, pre/post-test study was conducted. LLIN weekly use was assessed for four weeks before intervention and for another four weeks after intervention. The study was conducted in 96 households. The intervention consisted of testing four different weekly small change actions by using the MFI.ResultsOf the 96 households, 83 households (87%) owned at least one LLIN. However, only 40 households (42%) owned at least one LLIN for every two people. After intervention, the number of LLINs used increased from 32 to 75 per cent (134% increase) and the number of persons (general population) sleeping under LLIN from 35 to 73 per cent (108% increase). The number of children under 5 years old sleeping under LLIN increased from 31 to 76 per cent (145% increase) and the number of pregnant women who slept under LLIN from 43 to 73 per cent (69% increase). Also, the averages of the number of nights in each week that the general population slept under LLIN increased from 2.13 to 5.11 (140% increase), children under 5 years old slept under LLIN from 1.68 to 4.78 (184% increase) and pregnant women slept under LLIN from 1.56 to 4.47 (186% increase).ConclusionOur intervention led to significant increase in all outcome indicators. This increase is the result of a combination of an enabling context and an effective implementation of an evidence-based quality improvement intervention. Small tests of change at the community level have the potential for achieving improved outcomes.

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