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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Optimisation of container process at multimodal container terminals

Wong, Andy King-sing January 2008 (has links)
Multimodal container terminals are an important part of the logistics systems in international trade. Any improvement in the terminal efficiency is likely to reduce the costs of transporting goods, and to strengthen the trading position of the nation. During the import process, containers flow from ships to the storage yard for temporary storage and then are later moved to the hinterland by rail, or by road. The export process is the reverse of the import process. From the marshalling area, it is possible for a yard machine to carry an inbound container to the storage area and back with an inbound container in one round trip. This thesis investigates the inbound and outbound container process of multimodal container terminals in a multi-ship and multi-berth environment. The aim is to develop mathematical models and analytical tools for yard operation and planning. This study concerns the yardlayout, storage locations, operation strategies as well as the sequencing and scheduling of container process. Several models are developed for the scheduling of container process, taking account of planned and unplanned disruptions, and the intermediate buffer at the marshalling area. The problem is NP-hard and real-life problems often involve large number of containers. In addition, many schedules may not be feasible due to deadlock or violation of precedence-constraints. Good results were achieved on benchmark problems using the proposed innovative. In dealing with unplanned disruptions, reactive scheduling approach was found to give the results similar to as if the disruptions were planned in advance. Numerical investigations are also presented on various factors affecting the efficiency of seaport container terminals including the number of yard machines, and the number of quay crane. As with the various yard-layouts studied, it was found that containers are best stored in rows perpendicular to the quay-line with about 10 to 14 bays in each row. For a shorter ship service time, ideally the containers should be stored as close as possible to the ship. The best storage locations, however, are scarce resources and are not always available. Another model is developed for the best storage location as well as the best schedule for the container process. From an initial best schedule with predefined storage locations, the problem is solved by iterating through the refinement of storage scheme and re-scheduling. At a seaport terminal, ships are planned to arrive and leave within a scheduled time window. Nevertheless, a ship may arrive late due to poor weather conditions or disruptions at the previous port. Such delay may also affect its departure to the subsequent port. To minimise the impact of ship delays, port operators must consider alternate arrangements including re-assignment of berths, re-sequencing of ships and rescheduling of the container process. A ship delay model is developed and the problem is solved by combining branching and Tabu Search. The models developed in this thesis establish the relationship between significant factors and the options for increasing throughput by discovering the bottlenecks. The models are applicable as decision tools for operation planning, yard layout, and cost and benefit analysis for investment in infrastructures.
42

Teaching Idiomatic Expressions to Children with Developmental Delays Using the PEAK Relational Training System

Eberhardt, Brittney Elizabeth 01 December 2016 (has links)
AN ABSTRACT OF THE THESIS OF BRITTNEY E. EBERHARDT, for the Master of Science degree in Behavior Analysis and Therapy, presented on August 2016, at Southern Illinois University Carbondale. TITLE: TEACHING IDIOMATIC EXPRESSIONS TO CHILDREN WITH DEVELOPMENTAL DELAYS USING THE PEAK RELATIONAL TRAINING SYSTEM MAJOR PROFESSOR: Dr. Mark R. Dixon Idiomatic expressions are commonly used phrases, which require the listener to interpret the meaning figuratively rather than literally. The purpose of this study was to expand the research in the area of stimulus equivalence to determine whether untaught symmetrical and transitive responding in relation to idiomatic expressions would emerge for two participants with developmental delays. The first phase of the study involved directly training participants to respond with the statement (B stimuli; i.e.: “Go to bed.”) that corresponded with an intraverbal (A stimuli; i.e.: “What do you do at night after you put on your pajamas?”). After participants mastered these relationships, they were directly trained to respond with the idiomatic expression (C stimuli; i.e.: “Hit the hay”) when the experimenter verbally asked, “What is another way to say [A stimuli]?”. The results indicate that both participants achieved mastery criteria during the first phase of the study on A-B relations, however they were unable to demonstrate the derived equivalence A-C relation or C-B relation. After training on the B-C relationship, participants were again able to achieve criteria on the trained relationship and demonstrated some of the derived symmetrical relationships as well as derived transitive relationships. In addition, this study utilized the procedures from the PEAK-E relational training system to aid in replication in research and clinical practice.
43

Upgrade the Saudi Arabian Procurement System Delivery Method

January 2015 (has links)
abstract: Saudi Arabia has been having many issues with large construction projects such as delays, low performance and high cost. Some studies show that around 70% of the public projects in Saudi Arabia are delayed. These issues have resulted from many factors. One of the factors believed to be delaying projects is the Saudi procurement system. The Saudi procurement system only selects contracts based on the lowest bid price offered. However, the Saudi procurement system has been found to not only produce delayed low quality projects, but also has resulted in higher costs. This paper shows how to modify the Saudi procurement system by implementing a clarification phase, which is the most important phase in the Performance Information Procurement System (PIPS). The clarification phase requires the bid’s winning contractor to submit a project scope, a project schedule, to identify risks that not their responsibility, performance measurements and a milestone schedule. The PIPS system has been one of the most successful systems around the world and has shown a 98% success rate in six different countries with risks and cost reductions up to 30%. This research conducted a survey of 157 engineers, 33 consultants, 9 owners, 5 vendors, 13 academics, and 28 architects to develop the public procurement system in Saudi Arabia. The participants work in government sectors with an interest in the Saudi Arabian procurement system. 80.61 % of participants believe that the traditional Saudi procurement system consistently selects poor performing contractors. Moreover, 95.97% of participants think that the selection of contractors based only on the lowest price criterion affects projects negatively. Also, 96.20% of participants in the survey feel that there needs to be a change in the traditional Saudi Arabian procurement system. 88.7% of participants agree to require the contractor to identify risks, and 96.03 % of participants agree that the contractors must have a plan. Moreover, 95.45% of participants agree to require a contractor review the scope of a project and verify that it is correct. Finally, 82.18% of participants agree to require a contractor to resolve all owner concerns before signing a contract to improve construction projects performance. The paper shows the need to change the Saudi procurement system and a solution to this growing problem. / Dissertation/Thesis / Masters Thesis Construction 2015
44

Factors influencing delay in seeking tuberculosis treatment in Belet-Weyne District, Somalia

Nur, Abukar Yusuf January 2008 (has links)
Magister Public Health - MPH / Delays in seeking effective treatment for tuberculosis increase the level of disease morbidity and mortality rate as well as the risk of its transmission in the community (WHO, 2006b). In Somalia, Tuberculosis (TB) remains one of the greatest health threats as it is the leading cause of death in the economically active age groups and in people living with HIV/AIDS (WHO, 2004). This study was carried out with the aim of determining factors influencing delays in seeking TB treatment in Belet-Weyne district. / South Africa
45

LEAN maintenance model based on change management allowing the reduction of delays in the production line of textile SMEs in Peru

Arrascue-Hernandez, G., Cabrera-Brusil, J., Chavez-Soriano, P., Raymundo-Ibañez, C., Perez, M. 06 April 2020 (has links)
This article examines the problem of production line delays in a textile small- and medium-sized enterprise (SME) that produces polyester fibre from recycled bottles, based on orders. Factors that have resulted in production line delays include prolonged unscheduled maintenance time, and preparations and adjustments prior to operating the equipment. To address the problem, a model was developed applying lean manufacturing tools through change management, with the aim of increasing equipment availability and useful life. To validate the model, a pilot was developed to determine how the increase in equipment availability helps reduce delays in the production line, which eventually improves completion of customer orders.
46

Efficient flight schedules with utilizing Machine Learning prediction algorithms

Vandehzad, Mashhood January 2020 (has links)
While data is becoming more and more pervasive and ubiquitous in today’s life, businesses in modern societies prefer to take advantage of using data, in particular Big Data, in their decision-making and analytical processes to increase their product efficiency. Software applications which are being utilized in the airline industry are one of the most complex and sophisticated ones for which conducting of data analyzing techniques can make many decision making processes easier and faster. Flight delays are one of the most important areas under investigation in this area because they cause a lot of overhead costs to the airline companies on one hand and airports on the other hand. The aim of this study project is to utilize different machine learning algorithms on real world data to be able to predict flight delays for all causes like weather, passenger delays, maintenance, airport congestion etc in order to create more efficient flight schedules. We will use python as the programming language to create an artifact for our prediction purposes. We will analyse different algorithms from the accuracy perspective and propose a combined method in order to optimize our prediction results.
47

Identifying behavioral, demographic, and clinical risk factors for delayed access to emergency obstetrical care in preeclamptic women in Port au Prince, Haiti

Hutchinson, Katharine 06 November 2016 (has links)
OBJECTIVES: We conducted a mixed methods study of delayed access to emergency obstetrical care among preeclamptic and non-preeclamptic women in Port au Prince, Haiti, grounded in the Three Delays model of Thaddeus and Maine. The primary objectives were to identify factors affecting delays in accessing care and clinical consequences of delays. METHODS: 524 surveys were administered to women admitted to the Médecins Sans Frontières (MSF) obstetric emergency hospital. Survey questions addressed demographic, clinical, and behavioral risk factors; first (at home), second (transport) and third (health facility) delays; and clinical outcomes for women and infants. Bivariate statistics were used to assess relationships between preeclampsia status and delay, and between risk factors and delay. Twenty-six survey participants with lengthy delays (> 6 hours) were chosen for interviews, which elicited details about delays women experienced. Data were analyzed using a grounded theory approach. RESULTS: We found long delays to accessing care for preeclamptic women (median 5.0 hours, IQR 10.5, vs. 4.0 hours, IQR 5.0, for non-preeclamptic women, p<0.01), primarily due to delays at home before leaving for the hospital (median 2.6 hours, IQR 10.6). No demographic, clinical, or behavioral factors were related to access to care. Women's health prior to pregnancy was not associated with delays, with the exception of preeclamptic women who had previously seen a doctor, who had significantly longer delays than women who had not previously seen a doctor (22.8 hours versus 11.2 hours, p=0.02). Long delays for both preeclamptic and non-preeclamptic women were not associated with poorer clinical outcomes. Although the MSF hospital is free of charge, financial barriers at other hospitals limited access to emergency obstetric care for many women, who commonly experienced non-evidence-based care, including inappropriate education from antenatal care providers when diagnosed with hypertension or preeclampsia. CONCLUSIONS: Pregnant women with preeclampsia in Port au Prince reported significant delays in accessing emergency obstetric care. Many delays stemmed from poor quality antenatal care services, which fail to screen, treat, or educate women appropriately. Improvements should be made in education and supervision for antenatal care providers, and in accessibility of emergency services at public hospitals in Port au Prince.
48

The impact of variances and delays on nonroutine decisions and knowledge utilization in a product development organization

Purser, Ronald Edward January 1990 (has links)
No description available.
49

A System for Travel Time Estimation on Urban Freeways

Dhulipala, Sudheer 05 June 2002 (has links)
Travel time information is important for Advanced Traveler Information Systems (ATIS) applications. People traveling on urban freeways are interested in knowing how long it will take them to reach their destinations, particularly under congested conditions. Though many advances have been made in the field of traffic engineering and ITS applications, there is a lack of practical travel time estimation procedures for ATIS applications. Automatic Vehicle Identification (AVI) and Geographic Information System (GPS) technologies can be used to directly estimate travel times, but they are not yet economically viable and not widely deployed in urban areas. Hence, data from loop detectors or other point estimators of traffic flow variables are predominantly used for travel time estimation. Most point detectors can provide this data efficiently. Some attempts have been made in the past to estimate travel times from point estimates of traffic variables, but they are not comprehensive and are valid for only particular cases of freeway conditions. Moreover, most of these methods are statistical and thus limited to the type of situations for which they were developed and are not of much general use. The purpose of current research is to develop a comprehensive system for travel time estimation on urban freeways for ATIS applications. The system is based on point estimates of traffic variables obtained from detectors. The output required from the detectors is flow and occupancy aggregated for a short time interval of 5 minutes. The system for travel time estimation is based on the traffic flow theory rather than statistical methods. The travel times calculated using this system are compared with the results of FHWA simulation package TSIS 5.0 and the estimation system is found to give reasonable and comparable results when compared with TSIS results. / Master of Science
50

TIGHTER INTER-CORE DELAYS IN MULTI-CORE EMBEDDED SYSTEMS UNDER PARTITIONED SCHEDULING

Vidović, Tin, Hasanagić, Lamija January 2020 (has links)
There exists an increasing demand for computing power and performance in real-time embedded systems, as new, more complex customer requirements and function-alities are appearing every day. In order to support these requirements and func-tionalities without breaking the power consumption wall, many embedded systems areswitching from traditional single-core hardware architectures to multi-core architec-tures. Multi-core architectures allow for parallel execution of tasks on the multiplecores. This introduces many benets from the perspective of achievable performance,but in turn introduces major issues when it comes to the timing predictability ofthe real-time embedded system applications deployed on them. The problem arisesfrom unpredictable and potentially unbounded inter-core interferences, which occuras a result of contention for the shared resources, such as the shared system busor shared system memory. This thesis studies the possible application of constraintprogramming as a resource optimization technique for the purpose of creating oineschedules for tasks in real-time embedded system applications executing on a dual-core architecture. The main focus is placed on tightening inter-core data-propagationinterferences, which can result in lower over-all data-propagation delays. A proto-type of an optimization engine, employing constraint programming techniques on ap-plications comprised of tasks structured according to the Phased Execution Model isdeveloped. The prototype is evaluated through several experiments on a large numberof industry inspired intellectual-property free benchmarks. Alongside the experimentsa case study is conducted on an example engine-control application and the resultingschedule is compared to a schedule generated by the Rubus-ICE industrial tool suite.The obtained results show that the proposed method is applicable to a potentially widerange of abstract systems with dierent requirements. The limitations of the methodare also discussed and potential future work is debated based on these results. / <p>Presentation was held over Zoom, due to the COVID-19 situation.</p>

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