Study on Single-Machine Group Scheduling with Due-Window Assignment and Position-Dependent Weights

This article considers a single-machine group scheduling problem with due-window assignment, where the jobs are classified into groups and the jobs in the same group must be processed in succession. The goal is to minimize the weighted sum of lateness and due-window assignment cost, where the weights depend on the position in which a job is scheduled (i.e., position-dependent weights). For the common, slack, and different due-window assignment methods, we prove that the problem can be solved polynomially, i.e., in O N log N time, where N is the number of jobs.

Study of Three-Point Linkage of Power Machine

The three-point linkage serves to interconnect the power machine and the suspended or semi-suspended work machine. It has a role in the operation of the machine group, in towing and in the setup of the machines. Part of the weight of the suspended machine is loaded on the driven wheels, thus increasing the adhesion weight which results in an increase in the tractive force. Understanding the operation of this equipment it is necessary for horticulture, agronomy and landscape architecture future engineers. In this thesis we model the effect of connection points of the three-point linkage on the tractive force in a specific case: that of the suspended plow.

Effects of Resistance Training With Machines and Elastic Tubes on Functional Capacity and Muscle Strength in Community-Living Older Women: A Randomized Clinical Trial

The aim of the present study is to compare the effects of 12 weeks of resistance training with machines and elastic tubes on functional capacity and muscular strength in older women aged 60 years or over. The participants were randomized into two groups: a machine group (n = 23) and an elastic group (n = 20). They performed 12 weeks of progressive resistance training, twice a week, with similar exercises. Outcomes were assessed at three time points: baseline, postintervention, and 8 weeks after the end of the training. A significant intragroup effect was demonstrated for both groups at postintervention on functional tests and muscle strength. For the functional reach test and elbow flexion strength (180°/s), only the machine group demonstrated significant intragroup differences. No differences were observed between groups for any outcome. At the 8-week follow-up, functional capacity outcome values were maintained. The muscle strength outcome values decreased to baseline scores, without differences between groups.

Optimization of the organization of the forest road construction

Основной целью работы является оптимизация использования машин для земляных работ в строительстве лесных дорог по критерию минимума приведенных расходов, путем оптимального распределения комплектов машин по объектам строительства при условии возможности аренды какихлибо дополнительных машин. Создана экономикоматематическая модель расчета эффективной структуры парка машин с точки зрения системы производственной эксплуатации, которая складывается из эффектов всех специализированных комплектов машин и эффекта от передачи машин парка в аренду. Учет возможности передачи или получения техники в аренду позволяет улучшить техникоэкономические показатели эксплуатации парка машин. Результаты работы могут быть востребованы лесозаготовительными и дорожностроительными предприятиями в период проектирования производства земляных работ, обновления машинных парков, а также при выборе наилучшего варианта использования имеющегося парка, прогнозирования продолжительности и стоимости ведения механизированных работ. The main purpose of this work is to optimize the earthmoving machinery utilization in the forest road construction, by minimize the operating cost. That goal may achieve by the optimal distribution of the machine combination in the construction sites, with the ability of renting additional machines. Economical mathematical model has been developed for calculating the effective structure of the machine group to achieve the required productivity. The possibility of hire and rent machines allows the manager to improve the technical economic decision for the machines operation. By using the developed model it can gives good results to having better decisions for planning and designing the earth working operations in the road construction companies, renovation of the machine parks, as well as the choosing the best option for using the existing machine combination, predicting the duration and predicting the cost of the whole work.