Theoretical and Computational Research in Various Scheduling Models

Nine manuscripts were published in this Special Issue on “Theoretical and Computational Research in Various Scheduling Models, 2021” of the MDPI Mathematics journal, covering a wide range of topics connected to the theory and applications of various scheduling models and their extensions/generalizations. These topics include a road network maintenance project, cost reduction of the subcontracted resources, a variant of the relocation problem, a network of activities with generally distributed durations through a Markov chain, idea on how to improve the return loading rate problem by integrating the sub-tour reversal approach with the method of the theory of constraints, an extended solution method for optimizing the bi-objective no-idle permutation flowshop scheduling problem, the burn-in (B/I) procedure, the Pareto-scheduling problem with two competing agents, and three preemptive Pareto-scheduling problems with two competing agents, among others. We hope that the book will be of interest to those working in the area of various scheduling problems and provide a bridge to facilitate the interaction between researchers and practitioners in scheduling questions. Although discrete mathematics is a common method to solve scheduling problems, the further development of this method is limited due to the lack of general principles, which poses a major challenge in this research field

Lignite As Contributory Factor to Regional Development of Greece

Lignite (brown coal) is Greece's most important energy mineral raw material. Lignite exploitation has made a highly significant contribution to the development of energy sector of Greece on past 50 years, and will, according to estimations, continue to supply energy for another 40 years. Greece is very rich in Lignite resources. The two main basins - from where Lignite is extracted by opencast mining - are a) in Western Macedonia (northen Greece) where is generated the 70% of the whole electricity of Greece and b) in Central Peloponese (Southern Greece) where is generated the 10% of the whole electricity of Greece. In this respect, Public Power Corporation of Greece cooperates with the local administrative authorities and finances or undertakes social "compensation" projects for life improvement, and social and financial support of the residential areas near mines. Also provides technical services and contributes to the carrying out of small projects in municipalities and communities. Finaly provides thermal energy from the power stations for the district teleheating of the towns of Kozani, Ptolemais and Megalopolis and surrounting settlements. In addition to the works of social regeneration and the duty for the development of industrial areas, for the redevelopment works and environmental protection of the new ground at the lignite mines, more than 500.000 Euros are spent on a yearly basis (350.000 Euros at West Macedonia and 150.000 Euros at Central Peloponese). Moreover, according to data taken from the statement of accounts regarding only the operation of the mines (salaries, commossions, contracts assigned etc) the amount of 367.000.000 Euros is spent in the local societies of Kozani and Florina Prefectures. As a result, Lignite contributes to the regional Development of the country. Lignite mining and the generation of electric power take place in less developed areas, ensuring employment for a large number of scientific and labor personel, reducing unemployment and urban attraction and increasing the per capita local income in these areas.

Variable gravity research facility

Spin and despin requirements; sequence of activities required to assemble the Variable Gravity Research Facility (VGRF); power systems technology; life support; thermal control systems; emergencies; communication systems; space station applications; experimental activities; computer modeling and simulation of tether vibration; cost analysis; configuration of the crew compartments; and tether lengths and rotation speeds are discussed

Annual report of the town officers Swanzey, New Hampshire for the year ending December 31, 2004.

This is an annual report containing vital statistics for a town/city in the state of New Hampshire

Annual report of the town of Enfield, New Hampshire. Year ending December 31, 2005.

This is an annual report containing vital statistics for a town/city in the state of New Hampshire

Optimization of Fuel Consumption for Municipal Solid Waste Collection in Al Ain City, UAE

Collection and transportation of municipal solid waste (MSW) often account for a significant amount of the total budget allocated for waste management. A major portion of that is attributed to fuel consumption. Meanwhile, vehicles involved with waste collection can emit significant levels of atmospheric pollutants. Hence, optimization of waste collection yields both financial and environmental benefits. No work has been done to optimize fuel consumption during MSW collection in Al Ain city. In this study, several cases were developed using ArcGIS Network Analyst tool in order to establish optimum conditions for MSW collection in Um Gafa district in Al Ain city, with an objective function of minimization of fuel consumption. A geographic information system was created based on data collection and GPS tracking of collection route and bins position. The study revealed that waste collection at Um Gafa at the current time does not strictly follow U-turn and curb approach policies. When route optimization is applied for similar traffic conditions as the current ones, a saving of 14.3% in fuel consumption is gained. In addition, emitted CO2 is reduced by 7.2%. However, by strictly following the U-turn and curb approach policy of the traffic department, the relative saving in fuel consumption was much less (5%) as compared to the current practice of vehicle maneuvering for waste collection. Two new models were proposed for optimal number and location of bins. One model was based on a 40-m service zone while the other was based on population density and landuse. By adopting the first model, the number of bins was reduced by 12%, while in the second model the number of bins was reduced by 20%. In both models, more efficient routes in terms of fuel consumption and reduction in emissions have resulted, with second model showing superiority compared to the first model

Morton Electronics: The Collapse Of High-Performance, Self-Managed Work Teams

It was clear that top management was seriously pondering the long-term viability of Robert Mitchell’s manufacturing group…at least as it was currently structured.  Robert sat at his desk wondering what he could do to keep his job as manager and maintain control of the group. He concluded that he needed to do more than develop some kind of cost savings plan.  He needed to think outside the box and come up with something more spectacular to impress top management.  He would take the lemons and make lemonade

The Daily Texan

Texas Student Medi

19th century London dust-yards: A case study in closed-loop resource efficiency

The material recovery methods used by dust-yards in early 19th century London, England and the conditions that led to their development, success and decline are reported. The overall system developed in response to the market value of constituents of municipal waste, and particularly the high coal ash content of household ‘dust’. The emergence of lucrative markets for ‘soil’ and ‘breeze’ products encouraged dust-contractors to recover effectively 100% of the residual wastes remaining after readily saleable items and materials had been removed by the thriving informal sector. Contracting dust collection to the private sector allowed parishes to keep the streets relatively clean, without the need to develop institutional capacity, and for a period this also generated useful income. The dust-yard system is, therefore, an early example of organised, municipal-wide solid waste management, and also of public–private sector participation. The dust-yard system had been working successfully for more than 50 years before the Public Health Acts of 1848 and 1875, and was thus important in facilitating a relatively smooth transition to an institutionalised, municipally-run solid waste management system in England. The dust-yards can be seen as early precursors of modern materials recycling facilities (MRFs) and mechanical–biological treatment (MBT) plants; however, it must be emphasised that dust-yards operated without any of the environmental and occupational health considerations that are indispensable today. In addition, there are analogies between dust-yards and informal sector recycling systems currently operating in many developing countries