923 resultados para personnel and shift scheduling


Relevância:

100.00% 100.00%

Publicador:

Resumo:

This article argues that since 2000 successive Croatian governments have shown themselves increasingly dedicated to reforming civil-military relations. However, their efforts have been hampered by four key obstacles. First, the need to implement defence reforms in the context of an unwieldy set of civil-military relationships, political and institutional rivalries, a lack of civil and military defence expertise and a continuing legacy of politicisation. Second, the need to cut defence spending as a proportion of the overall budget whilst taking on new military roles and improving the capability of the armed forces. Third, the need to balance the demands of the NATO accession process while implementing a balanced and fundamental reform of the armed forces as a whole. Finally, the need to implement root and branch personnel reforms and downsizing in the OSRH while simultaneously recruiting and retaining quality personnel and addressing the wider social issue of unemployment.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Investment in mining projects, like most business investment, is susceptible to risk and uncertainty. The ability to effectively identify, assess and manage risk may enable strategic investments to be sheltered and operations to perform closer to their potential. In mining, geological uncertainty is seen as the major contributor to not meeting project expectations. The need to assess and manage geological risk for project valuation and decision-making translates to the need to assess and manage risk in any pertinent parameter of open pit design and production scheduling. This is achieved by taking geological uncertainty into account in the mine optimisation process. This thesis develops methods that enable geological uncertainty to be effectively modelled and the resulting risk in long-term production scheduling to be quantified and managed. One of the main accomplishments of this thesis is the development of a new, risk-based method for the optimisation of long-term production scheduling. In addition to maximising economic returns, the new method minimises the risk of deviating from production forecasts, given the understanding of the orebody. This ability represents a major advance in the risk management of open pit mining.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The importance of technology to developing countries is widely recognised as they compete internationally and develop internally. Firms acquire technology by different means and from diverse sources, and they possess varying levels of competence. Since countries are at various stages of economic and technological development, prescriptive approaches to technology and operations integration are not appropriate. The paper discusses factors in the literature that affect the integration of technology and operations in developing countries. Country similarities and differences also play a role, so the study examines three developing countries: Brazil, India and South Africa. These countries are emerging from periods of regulation and have developed certain sectors of their economies. Empirical evidence is provided from a study of managers in South Africa who were asked to assess the important factors in technology integration, and to score the extent to which they can control these. Results from the study concur with the literature regarding the importance of a country’s political stability and its policies towards new investment and infrastructure. Knowledge and understanding of technology are essential for successful integration in countries with insufficient skilled personnel, and where education levels are low.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Purpose – The purpose of this research is to study the perceived impact of some factors on the resources allocation processes of the Nigerian universities and to suggest a framework that will help practitioners and academics to understand and improve such processes. Design/methodology/approach – The study adopted the interpretive qualitative approach aimed at an ‘in-depth’ understanding of the resource allocation experiences of key university personnel and their perceived impact of the contextual factors affecting such processes. The analysis of individual narratives from each university established the conditions and factors impacting the resources allocation processes within each institution. Findings – The resources allocation process issues in the Nigerian universities may be categorised into people (core and peripheral units’ challenge, and politics and power); process (resources allocation processes); and resources (critical financial shortage and resources dependence response). The study also provides insight that resourcing efficiency in Nigerian universities appears strongly constrained by the rivalry among the resource managers. The efficient resources allocation process (ERAP) model is proposed to resolve the identified resourcing deficiencies. Research limitations/implications – The research is not focused to provide generalizable observations but ‘in-depth’ perceived factors and their impact on the resources allocation processes in Nigerian universities. The study is limited to the internal resources allocation issues within the universities and excludes the external funding factors. The resource managers’ responses to the identified factors may affect their internal resourcing efficiency. Further research using more empirical samples is required to obtain more widespread results and the implications for all universities. Originality/value – This study contributes a fresh literature framework to resources allocation processes focusing at ‘people’, ‘process’ and ‘resources’. Also a middle range theory triangulation is developed in relation to better understanding of resourcing process management. The study will be of interest to university managers and policy makers.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In recent years, offshoring and outsourcing have transformed fundamentally nationally based auto sectors into global networks of design, production and distribution across the global value chains coordinated by the major automotive Original Equipment Manufacturers (OEMs). As manufacturing activities tended to be shifted to low-labour cost locations in Asia, Africa and Latin America, high-end design, R&D, product development have stayed anchored mostly to high-cost and high knowledge-intensive home economy locations (perhaps with the except of some design and styling activities which are often located in major end markets around the world. However, very recently the weaknesses of and risks inherent in such global value chains (GVCs) have been exposed, triggering attempts to rethink their nature and also raising possibilities to reshore some manufacturing activities to home countries. A combination of a more competitive exchange rate (despite the very recent appreciation of sterling), increased transport costs, rising wages in key areas of China, and a greater awareness of supply chain resilience have all contributed to a perceived change in some business fundamentals. The potential for some supply chain relocalisation also links in with the servitisation of manufacturing including the auto sector and shift to a hybrid model where manufacturing and services are increasingly intertwined. However, there are limits as to how far this can go and these raise some important questions and issues over the possible role for industrial policy.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Buffered crossbar switches have recently attracted considerable attention as the next generation of high speed interconnects. They are a special type of crossbar switches with an exclusive buffer at each crosspoint of the crossbar. They demonstrate unique advantages over traditional unbuffered crossbar switches, such as high throughput, low latency, and asynchronous packet scheduling. However, since crosspoint buffers are expensive on-chip memories, it is desired that each crosspoint has only a small buffer. This dissertation proposes a series of practical algorithms and techniques for efficient packet scheduling for buffered crossbar switches. To reduce the hardware cost of such switches and make them scalable, we considered partially buffered crossbars, whose crosspoint buffers can be of an arbitrarily small size. Firstly, we introduced a hybrid scheme called Packet-mode Asynchronous Scheduling Algorithm (PASA) to schedule best effort traffic. PASA combines the features of both distributed and centralized scheduling algorithms and can directly handle variable length packets without Segmentation And Reassembly (SAR). We showed by theoretical analysis that it achieves 100% throughput for any admissible traffic in a crossbar with a speedup of two. Moreover, outputs in PASA have a large probability to avoid the more time-consuming centralized scheduling process, and thus make fast scheduling decisions. Secondly, we proposed the Fair Asynchronous Segment Scheduling (FASS) algorithm to handle guaranteed performance traffic with explicit flow rates. FASS reduces the crosspoint buffer size by dividing packets into shorter segments before transmission. It also provides tight constant performance guarantees by emulating the ideal Generalized Processor Sharing (GPS) model. Furthermore, FASS requires no speedup for the crossbar, lowering the hardware cost and improving the switch capacity. Thirdly, we presented a bandwidth allocation scheme called Queue Length Proportional (QLP) to apply FASS to best effort traffic. QLP dynamically obtains a feasible bandwidth allocation matrix based on the queue length information, and thus assists the crossbar switch to be more work-conserving. The feasibility and stability of QLP were proved, no matter whether the traffic distribution is uniform or non-uniform. Hence, based on bandwidth allocation of QLP, FASS can also achieve 100% throughput for best effort traffic in a crossbar without speedup.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This research is motivated by the need for considering lot sizing while accepting customer orders in a make-to-order (MTO) environment, in which each customer order must be delivered by its due date. Job shop is the typical operation model used in an MTO operation, where the production planner must make three concurrent decisions; they are order selection, lot size, and job schedule. These decisions are usually treated separately in the literature and are mostly led to heuristic solutions. The first phase of the study is focused on a formal definition of the problem. Mathematical programming techniques are applied to modeling this problem in terms of its objective, decision variables, and constraints. A commercial solver, CPLEX is applied to solve the resulting mixed-integer linear programming model with small instances to validate the mathematical formulation. The computational result shows it is not practical for solving problems of industrial size, using a commercial solver. The second phase of this study is focused on development of an effective solution approach to this problem of large scale. The proposed solution approach is an iterative process involving three sequential decision steps of order selection, lot sizing, and lot scheduling. A range of simple sequencing rules are identified for each of the three subproblems. Using computer simulation as the tool, an experiment is designed to evaluate their performance against a set of system parameters. For order selection, the proposed weighted most profit rule performs the best. The shifting bottleneck and the earliest operation finish time both are the best scheduling rules. For lot sizing, the proposed minimum cost increase heuristic, based on the Dixon-Silver method performs the best, when the demand-to-capacity ratio at the bottleneck machine is high. The proposed minimum cost heuristic, based on the Wagner-Whitin algorithm is the best lot-sizing heuristic for shops of a low demand-to-capacity ratio. The proposed heuristic is applied to an industrial case to further evaluate its performance. The result shows it can improve an average of total profit by 16.62%. This research contributes to the production planning research community with a complete mathematical definition of the problem and an effective solution approach to solving the problem of industry scale.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This research aims at a study of the hybrid flow shop problem which has parallel batch-processing machines in one stage and discrete-processing machines in other stages to process jobs of arbitrary sizes. The objective is to minimize the makespan for a set of jobs. The problem is denoted as: FF: batch1,sj:Cmax. The problem is formulated as a mixed-integer linear program. The commercial solver, AMPL/CPLEX, is used to solve problem instances to their optimality. Experimental results show that AMPL/CPLEX requires considerable time to find the optimal solution for even a small size problem, i.e., a 6-job instance requires 2 hours in average. A bottleneck-first-decomposition heuristic (BFD) is proposed in this study to overcome the computational (time) problem encountered while using the commercial solver. The proposed BFD heuristic is inspired by the shifting bottleneck heuristic. It decomposes the entire problem into three sub-problems, and schedules the sub-problems one by one. The proposed BFD heuristic consists of four major steps: formulating sub-problems, prioritizing sub-problems, solving sub-problems and re-scheduling. For solving the sub-problems, two heuristic algorithms are proposed; one for scheduling a hybrid flow shop with discrete processing machines, and the other for scheduling parallel batching machines (single stage). Both consider job arrival and delivery times. An experiment design is conducted to evaluate the effectiveness of the proposed BFD, which is further evaluated against a set of common heuristics including a randomized greedy heuristic and five dispatching rules. The results show that the proposed BFD heuristic outperforms all these algorithms. To evaluate the quality of the heuristic solution, a procedure is developed to calculate a lower bound of makespan for the problem under study. The lower bound obtained is tighter than other bounds developed for related problems in literature. A meta-search approach based on the Genetic Algorithm concept is developed to evaluate the significance of further improving the solution obtained from the proposed BFD heuristic. The experiment indicates that it reduces the makespan by 1.93 % in average within a negligible time when problem size is less than 50 jobs.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Public schools traditionally have been held accountable for educating the majority of the nation’s school children, and through the years, these schools have been evaluated in a variety of ways. Currently, evaluation measures for accountability purposes consist solely of standardized test scores. In the past, only test scores of general education students were analyzed. Laws governing the education of students with disabilities, however, have extended accountability measures not only to include those students, but to report their scores in a disaggregated form (No Child Left Behind Act, 2001). The recent emphasis on accountability and compliance has resulted in the need for schools to carefully examine how programs, services, and policies impact student achievement (Bowers & Figgers, 2003). ^ Standard-based school reform and accountability systems have raised expectations about student learning outcomes for all students, including those with disabilities and minority students. Yet, overall, racial/ethnic minority students are performing well below their White non-Hispanic peers in most academic areas. Additionally, with respect to special education, there exists an enduring problem of disproportionate representation of racial/ethnic minority students (National Research Council, 2000). ^ This study examined classroom placement (inclusive versus non-inclusive) relative to academic performance of urban, low socioeconomic Hispanic students with and without disabilities in secondary content area classrooms. A mixed method research design was used to investigate this important issue using data from a local school district and results from field observations. The study compared performance levels of four middle school Hispanic student subgroups (students with disabilities in inclusive settings, students without disabilities in inclusive settings, students with disabilities in resource settings, and student without disabilities in general education settings) each in their respective placements for two consecutive years, exploring existing practices within authentic settings. ^ Significant differences were found in the relationship of educational placement and achievement between grade level and disability in the areas of math and reading. Additionally, clear and important differences were observed in student-teacher interactions. Recommendations for further researchers and stakeholders include soliciting responses from teams at the schools composed of general education and special education teachers, administrative personnel, and students as well as broadening the study across grade levels and exceptionalities. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

With the beginning of airline deregulations in 1978, U.S. domestic operations were in for a period of turmoil, adjustment, vibrancy, entrepreneurship, and change. A great deal has been written about the effects of deregulation on airlines and their personnel, and on the public at large. Less attention has been paid to the effects on travel agents and on the seminal role of computerized reservations systems (CRSs) in the flowering of travel agencies. This article examines both of these phenomena.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The purpose of this dissertation was to determine the interactions of sexuality and education among low socioeconomic status first and second generation Mexican immigrant adolescent girls. Much of the existing research differentiates between immigrant generations with little examination of the differences within a particular immigrant generation. This study utilized qualitative methods to examine how various social institutions intersected to influence the young women's decisions about education and sexuality. The methodology included more than three years of participant observation in a South Florida high school and surrounding community; structured and unstructured interviews with twenty young women, their family members, school personnel, and community activists; and surveys conducted with the young women and their parent or guardian. ^ Moving beyond the limits of essentialist immigration theories, this project revealed within group (i.e. immigrant generation) complexities as well as between group similarities. The data included in this dissertation delineate how relationships of power and control permeated the lives of first and second generation Mexican immigrant adolescent girls. The lens of this dissertation is focused on the salient issues of sexuality and education: two dominant forces in many adolescent lives. ^ I found the young women represented a variety of positions on the academic orientation and sexuality continuums and engaged in activities that both reinforced and countered their stated positions on each of these issues. Specifically, first and second generation immigrants are often viewed as maintaining opposing viewpoints about both education and female sexuality however, for these young women the within group variation was larger than the between group variation. While all the young women in this study expressed a belief in the value of education, they engaged in activities that both fortified and contradicted that expressed position. Additionally, although acculturation can lead to increased sexual activity and decreased engagement with education, the first generation immigrant young women in this study became pregnant and/or withdrew from school in equal proportions to their second generation counterparts. In summary, structural forces combined, often inadvertently, and contributed to these young women's spiraling negative academic orientation and/or rational choice of motherhood. Finally, the findings are linked to policy implications. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The objective of this research was to investigate the reason lumps occur in high-slump concrete and develop adequate batching procedures for a lumps-free high-slump ready-mix concrete mix used by the Florida Department of Transportation. Cement balls are round lumps of cement, sand, and coarse aggregate, typically about the size of a baseball that frequently occur in high-slump concrete. Such lumps or balls jeopardize the structural integrity of structural members. Experiments were conducted at the CSR Rinker concrete plant in Miami, Florida, based on a protocol developed by a team of Florida Department of Transportation (FDOT) concrete engineers, Rinker personnel, and Florida International University faculty. A total of seventeen truckloads were investigated in two phases, between April 2001 and March 2002. The tests consisted of gathering data by varying load size, discharge rate, headwater content, and mixing revolutions. The major finding was that a usual load size and discharge rate, an initial headwater ratio of 30%, and an initial number of revolutions of 100 at 12 revolutions per minute seem to produce a lump-free high-slump concrete. It was concluded that inadequate mixing and batching procedures caused cement lumps. Recommendations regarding specific load size, discharge rates, number of mixing revolutions, and initial water content are made. Clear guidelines for a high-slump concrete batching protocol can be developed, with further testing based on these research conclusions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

“Availability” is the terminology used in asset intensive industries such as petrochemical and hydrocarbons processing to describe the readiness of equipment, systems or plants to perform their designed functions. It is a measure to suggest a facility’s capability of meeting targeted production in a safe working environment. Availability is also vital as it encompasses reliability and maintainability, allowing engineers to manage and operate facilities by focusing on one performance indicator. These benefits make availability a very demanding and highly desired area of interest and research for both industry and academia. In this dissertation, new models, approaches and algorithms have been explored to estimate and manage the availability of complex hydrocarbon processing systems. The risk of equipment failure and its effect on availability is vital in the hydrocarbon industry, and is also explored in this research. The importance of availability encouraged companies to invest in this domain by putting efforts and resources to develop novel techniques for system availability enhancement. Most of the work in this area is focused on individual equipment compared to facility or system level availability assessment and management. This research is focused on developing an new systematic methods to estimate system availability. The main focus areas in this research are to address availability estimation and management through physical asset management, risk-based availability estimation strategies, availability and safety using a failure assessment framework, and availability enhancement using early equipment fault detection and maintenance scheduling optimization.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The continuous advancement in computing, together with the decline in its cost, has resulted in technology becoming ubiquitous (Arbaugh, 2008, Gros, 2007). Technology is growing and is part of our lives in almost every respect, including the way we learn. Technology helps to collapse time and space in learning. For example, technology allows learners to engage with their instructors synchronously, in real time and also asynchronously, by enabling sessions to be recorded. Space and distance is no longer an issue provided there is adequate bandwidth, which determines the most appropriate format such text, audio or video. Technology has revolutionised the way learners learn; courses are designed; and ‘lessons’ are delivered, and continues to do so. The learning process can be made vastly more efficient as learners have knowledge at their fingertips, and unfamiliar concepts can be easily searched and an explanation found in seconds. Technology has also enabled learning to be more flexible, as learners can learn anywhere; at any time; and using different formats, e.g. text or audio. From the perspective of the instructors and L&D providers, technology offers these same advantages, plus easy scalability. Administratively, preparatory work can be undertaken more quickly even whilst student numbers grow. Learners from far and new locations can be easily accommodated. In addition, many technologies can be easily scaled to accommodate new functionality and/ or other new technologies. ‘Designing and Developing Digital and Blended Learning Solutions’ (5DBS), has been developed to recognise the growing importance of technology in L&D. This unit contains four learning outcomes and two assessment criteria, which is the same for all other units, besides Learning Outcome 3 which has three assessment criteria. The four learning outcomes in this unit are: • Learning Outcome 1: Understand current digital technologies and their contribution to learning and development solutions; • Learning Outcome 2: Be able to design blended learning solutions that make appropriate use of new technologies alongside more traditional approaches; • Learning Outcome 3: Know about the processes involved in designing and developing digital learning content efficiently and what makes for engaging and effective digital learning content; • Learning Outcome 4: Understand the issues involved in the successful implementation of digital and blended learning solutions. Each learning outcome is an individual chapter and each assessment unit is allocated its own sections within the respective chapters. This first chapter addresses the first learning outcome, which has two assessment criteria: summarise the range of currently available learning technologies; critically assess a learning requirement to determine the contribution that could be made through the use of learning technologies. The introduction to chapter one is in Section 1.0. Chapter 2 discusses the design of blended learning solutions in consideration of how digital learning technologies may support face-to-face and online delivery. Three learning theory sets: behaviourism; cognitivism; constructivism, are introduced, and the implication of each set of theory on instructional design for blended learning discussed. Chapter 3 centres on how relevant digital learning content may be created. This chapter includes a review of the key roles, tools and processes that are involved in developing digital learning content. Finally, Chapter 4 concerns delivery and implementation of digital and blended learning solutions. This chapter surveys the key formats and models used to inform the configuration of virtual learning environment software platforms. In addition, various software technologies which may be important in creating a VLE ecosystem that helps to enhance the learning experience, are outlined. We introduce the notion of personal learning environment (PLE), which has emerged from the democratisation of learning. We also review the roles, tools, standards and processes that L&D practitioners need to consider within a delivery and implementation of digital and blended learning solution.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Thesis (Ph.D.)--University of Washington, 2016-08