Computer Optimization Model Research Articles

Patellofemoral Joint Loading During the Performance of the Wall Squat and Ball Squat with Heel-to-Wall-Distance Variations.

While bodyweight wall and ball squats are commonly used during patellofemoral rehabilitation, patellofemoral loading while performing these exercises is unknown, which makes it difficult for clinicians to know how to use these exercises in progressing a patient with patellofemoral pathology. Therefore, the purpose was to quantify patellofemoral force and stress between two bodyweight squat variations (ball squat-versus-wall-squat) and between two heel-to-wall-distance (HTWD) variations (long-HTWD versus short-HTWD). Sixteen participants performed a dynamic ball squat and wall squat with long HTWD and short HTWD. Ground reaction force and kinematic data were used to measure resultant knee force and torque from inverse dynamics, while electromyographic data were used in a knee muscle model to predicted resultant knee force and torque, and subsequently all these data were inputted into a biomechanical computer optimization model in order to output patellofemoral joint force and stress at select knee angles. A repeated measures 2-way and 3-way ANOVA (p < 0.01) was employed for statistical analyses. Collapsed across long-HTWD and short-HTWD, patellofemoral joint force and stress were greater in ball squat than wall squat at 30° (p = 0.009), 40° (p = 0.008), 90° (p = 0.003), and 100° (p = 0.005) knee angle during the squat descent, and greater in wall squat than ball squat at 100° (p < 0.001), 90° (p < 0.001), 80° (p = 0.004), and 70° (p = 0.009) knee angle during squat ascent. Collapsed across ball & wall squats, patellofemoral joint force & stress were greater with a short HTWD than a long HTWD at 100° (p = 0.007) and 90° (p = 0.008) knee angle during squat ascent. Patellofemoral joint loading changed according to both squat type and HTWD variations. These differences occurred in part due to differences in forces the wall or ball exerted on the trunk, including friction forces. Overall, patellofemoral force and stress were greater performing the bodyweight wall squat compared to the bodyweight ball squat. Moreover, squatting with short-HTWD produced anterior knee displacement beyond the toes at higher knee angles, resulting in greater patellofemoral force and stress compared to squatting with long-HTWD.

GENETIC PROGRAMMING FOR BRICK'S CHEMICAL ANALYSIS MODELLING

This study is part of the search for a sediment management methodology and the basic material that is designed for the manufacture of fired brick, in which we tackle the problem of choosing the mud samples from dredging the Algerian dams in particular (Bouhanifia dam western Algeria) and the choice of clay that comes from different deposits. We propose an approach for sampling using a computer optimization model that allows solving and optimizing a characterization to retain the best adapted sample (chemically) using the genetic algorithm.Keywords: Sludge- Dredging- Sample- Chemical Characterization- Brick-Optimization Methods- Genetic Algorithm.

Strategic optimization for implementing the Jordanian National Water Master Plan

The Jordan National Water Master Plan integrates multiple efforts to address the national water shortage, but suffers problems in implementation. The systems analysis-based approach proposed here involves stakeholders in defining: study areas/issues, flow limits (based on infrastructural, sustainability and management reasons), and the optimization objective function. The approach includes using a newly developed computer optimization model to speed analysis of stakeholder proposals. The optimization model calculates multi-period water distribution and allocation strategies, minimizing unsatisfied demand or optimizing economic effect. Implementing the approach would identify opportunities for improving water supply, conveyance and demand management, and help investment planning and international negotiations. It is transferable to other countries.

A Computational Model for Optimization on International Telecommunication Networks

Telecommunication networks are characterised by a complex group of intermediaries and each one of them faces two types of operational costs: transmission costs and delivery cost. This scheme allows the operator to evaluate the market structure and to perform the telecommunication service. The first aim of the paper is to model this scenario and implement an optimisation tool giving a support in optimal routing decision making. Given a existing and non-changeable network structure which is reliable to a short term perspective, the input of the N.E.O.S. (Network Optimisation System) tool consists in a set of structured arrays describing the various components of the market (i.e. customers, suppliers, unit transmission costs etc). The system allows the decision maker to create a customised data framework and performs linear optimisation in order to find the best routing solution for traffic demand. All the results can be graphically displayed following the output steps creating a monitor for decision making. Finally the tool is able to predict the income level related to the routing given solution. The second part of the paper tells indeed the optimal number of circuits relaxing the constraint of a given network structure; the latter could be related to a medium term perspective. The tool is implemented by using MATLAB software.

Evaluating International Ethical Climates: A Goal Programming Model

A critical concern for firms pursuing international expansion strategies involves identifying countries that offer a good fit with the firm's overall ethical orientation. Unfortunately, little has been written to aid firms in identifying countries that offer this type of fit. This paper presents a model that combines the concepts of strategic management, cross-cultural management, business ethics, and the management science technique of goal programming. The purpose of the model is to aid managers in identifying countries for international expansion that offer the best fit with the firm's ethical orientation. The paper also extends the existing literature on cross-cultural management and business ethics by applying a computer optimization model to evaluate potential countries for international expansion in a way that has not been done before.

A Two Stage Model for the Introduction of Products into International Markets

A critical concern for firms pursuing international expansion strategies involves selecting the best countries/markets within which to introduce their products and then selecting the best cities within the selected countries/markets to test market the products. In order for product introduction to be successful, corporations must identify countries and test market cities that offer a good fit with the firm's overall marketing strategy. Unfortunately, little has been written to aid corporations in making complex decisions involving the introduction of products into new international markets. This paper presents a two stage model that combines the concepts of marketing strategy, the management science technique of goal programming, and micro computer technology to provide managers with a more effective and efficient method for evaluating international markets and test market cities. The paper extends the existing literature on product introduction by applying a computer optimization model to country/market selection in a way that has not been done before.

Test market city evaluation: a goal programming approach

A critical concern for corporations test marketing new products involves test market city evaluation. In order for test marketing to be successful, corporations must identify cities that offer a good fit with the firm’s overall product strategy. Unfortunately, little has been written to aid corporations in making complex test city selection decisions. Presents a model that combines the concepts of marketing, the management science technique of goal programming, and microcomputer technology to provide managers with a more effective and efficient method for evaluating test cities and making selection decisions. Extends the existing literature on test market evaluation by applying a computer optimization model to test market evaluation in a way that has not been done before.