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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.
251

Structural analysis models for block pallets

Colclough, Robert G. January 1987 (has links)
A large percentage of the total annual lumber production in the U.S.A is consumed by the pallet industry. However, standardized design procedures for these products have only recently been developed. A four-year cooperative pallet research, development and application program was undertaken by the National Wooden Pallet and Container Association, Virginia Polytechnic Institute and State University, and the U.S Forest Service. This research is directed towards developing standardized design procedures for both stringer and block-type pallets. Phase I dealt exclusively with stringer-type pallets while Phase II expands the scope to include block-type pallets. The objective of this work was to develop methods to analyze the effects of loads, supports and geometry on the response of block-style pallets. The developed analysis procedures are based on matrix structural analysis methods. A quarter symmetric 3-dimensional model is used to simulate pallets racked across the stringerboards (RAS) and a half symmetric 2-dimensional model is used for the racked across deckboards (RAD) and sling support modes. Both models are used in the stack condition. Deckboard/stringerboard joints are modeled as a single spring in the RAS model and the deck-block joint in both the RAS and RAD models are modeled as a framework of rigidly connected members and five springs (2 rotational and three axial). The procedure has the capability to handle both uniformly distributed and line loads in rack, stack, or sling support modes, and a wide variety of commonly used geometries. The developed analysis methodology is presented in computerized form and will provide the user a means of communication with pallet manufacturers for defining expected performance. / M.S.
252

The flexural strength and stiffness of eastern oak pallet shook

Spurlock, Harvey W. January 1982 (has links)
An investigation was conducted to provide information concerning the flexural behavior of oak pallet shook. This information is to be used in the development of a rational pallet design procedure. The investigation was designed to meet three basic objectives 1) to collect basic data concerning the flexural properties of oak shook, 2) to evaluate the potential of a visual grading system and 3) to investigate the impact of growth and manufacturing defects on the flexural properties of oak pallet shook. Strength, stiffness and selected physical property values were determined and reported. The visual grading system was found to be effective at separating oak pallet shook on the basis of strength and stiffness. A comparison of test results with published procedures indicates strength ratios may be an effective approach to accounting for the influence of growth and manufacturing defects found in oak pallet shook. / M.A.
253

Economies of Scale in International Liner Shipping and Ongoing Industry Consolidation: an Application of Stigler's Survivorship Principle

Gregory, Karen V. 12 February 2000 (has links)
The international liner shipping industry has been undergoing major structural changes caused by a number of factors. Liner companies have responded to these challenges by engaging in mergers and acquisitions and by forming global strategic alliances. Many of these organizational changes have reportedly been undertaken to achieve, among other things, economies of scale. This paper systematically addresses two questions — whether there are economies of scale in international liner shipping, and if so, what are the implications of those economies for industry structure. To determine whether scale advantages exist, George Stigler's "Survivorship Principle" is used with current data in three phases. All three phases of the study show that increasing returns to scale are present. In each application of the survivorship test, small and medium sized firms experienced significant decline in their share of the industry's capacity, while the largest firms continued to gain market share over the 20-year test period. The existence of economies of scale at both the firm and plant level is most pronounced during the shorter 1987-1997 period, subsequent to significant regulatory changes. The study empirically verifies that economies of scale in liner shipping have been increasing in response to technology-driven productivity growth, regulatory changes, and higher world-wide trade flows. The pursuit of economies of scale also appears to be contributing to the consolidation occurring in the industry today via both mergers and acquisitions, and the formation of global strategic alliances. Lastly, the study discusses the implications of economies of scale on firm structure within the context of current industry economics, and evaluates business strategies presently being pursued. / Master of Arts
254

Social media engagement of stakeholders: A decision tree approach in container shipping

Surucu-Balci, Ebru, Balci, G., Yuen, K.F. 11 November 2019 (has links)
Yes / Social media provides a significant avenue for stakeholder engagement which is crucial to ensure loyalty and satisfaction of stakeholders who possess valuable resources that can influence the business outcomes. Container lines – imperative members of global supply chains and facilitators of international trade – utilize social media to engage their stakeholders due to environmental and commercial complexity of their business. However, not all social media posts generate the same amount of stakeholder engagement. This study aims to identify and examine the social media post characteristics that lead to higher stakeholder engagement in the container shipping market. The study applies Chi-Squared Automatic Interaction Detection method to categorize social media posts based on their engagement levels. The analysis is conducted on the tweets of four global container lines which are posted between 1 September 2018 and 31 January 2019. The results demonstrate that social media posts of container lines have varying effects on engagement level. We found that fluency of tweets, tangibility of company resources in the tweet, vividness level, content type, existence of a link, and existence of a call-to-action significantly influence the container lines’ stakeholder engagement rate. This study is the first that finds out social media post classes based on the interaction between their characteristics and engagement rates by employing a decision tree methodology. The results are expected to help container lines in their social media management and stakeholder engagement policies.
255

Blockchain adoption in the maritime supply chain: Examining barriers and salient stakeholders in containerized international trade

Balci, G., Surucu-Balci, Ebru 17 November 2021 (has links)
Yes / This study aimed to investigate the relationships between blockchain adoption barriers and identified the salient stakeholders for blockchain adoption in containerized international trade. The interpretative structural modelling and Cross-Impact Matrix Multiplication Applied to Classification analyses indicated that the most impactful among the eight barriers are lack of support from influential stakeholders, lack of understanding regarding blockchain, and lack of government regulations. The stakeholder mapping analysis demonstrated that the high salient stakeholders among 11 legitimate stakeholders are container lines, ports, beneficial cargo owners, freight forwarders/third party logistics, and customs authorities. The study is original and contributes to theory and practice as it uncovers both impactful barriers and critical stakeholders by adopting a stakeholder theory perspective and offers significant implications to practice, policy, and theory by combining these two analyses.
256

Inlandssjöfarten i andra delar av Europa kontra Sverige

Garin, Anders Fabian, Andréasson, Carl Viktor January 2024 (has links)
No description available.
257

A reliability based design procedure for wood pallets

Loferski, Joseph R. January 1985 (has links)
Pallets are widely used to efficiently store and handle goods and are often subjected to bending and impact loads. The consequences of structural failure of a loaded pallet can include loss of goods, increased labor and equipment costs, and possible severe or fatal injury to humans. - The pallet industry, which annually consumes nearly 20% of all lumber manufactured in the United States, recognized a need for a rational design methodology, based upon engineering principles, to ensure consistent safety and economy in pallets of any geometry. To satisfy this need a cooperative research project between Virginia Tech, the U. S. Forest Service, and the National Wooden Pallet and Container Association was established. The objective of the project was to develop methods to design pallets for strength, stiffness, and durability. A primary expected benefit of the design methodology is to allow comparison of different pallet designs on a performance basis, without the need for extensive physical testing. This dissertation presents the results of this cooperative research project. The developed methodology was computerized (Pallet Design System (PDS)) and is intended to allow pallet manufactures to obtain estimates of the maximum safe load capacity or the member dimensions required to resist known loads. Additionally, the program produces estimates of the durability and cost-per-use for pallets in specific service environments. PDS is limited in scope to pallets with up to four stringers and a maximum of 15 deckboards. Five different load types and four support modes can be analyzed. These include uniformly distributed and concentrated loads, and racked, stacked, and sling support modes. The techniques for estimating the strength and stiffness are based on matrix structural analysis and classical beam theory. The deckboard-stringer joints are modeled as spring elements, the stiffness of which are based upon characteristics of the fastener. Most fasteners commonly used in pallet construction (i.e. threaded nails or staples) can be analyzed. A probabilistic design technique based on mean value methods was applied in PDS to ensure safety in the resulting designs. The safety index was calibrated to pallet designs associated with warehouse load data. The physical properties of the material are estimated using either a modified clear-wood property approach (ASTM D-245 method), or in·graded testing of pallet lumber. The durability estimates are based upon studies of field data and economic analysis. / Ph. D.
258

Radio and satellite tracking and detecting systems for maritime applications

Skoryk, Ivan 15 January 2015 (has links)
Submitted in fulfillment of the requirements of the Doctor of Technology Degree in Information Technology, Durban University of Technology, Durban, South Africa, 2014. / The work described in this thesis summarizes the author’s contributions to the design, development and testing of embedded solutions for maritime Radio and Satellite tracking and detecting systems. In order to provide reliable tracking and detecting facilities of ships have to be integrated Convectional Maritime Radio Communications (CMRC) and Maritime Mobile Satellite Communications (MMSC) systems. On the other hand, Global Mobile Satellite Communications (GMSC) as a part of Global Communication Satellite Systems (GCSS) has to be integrated with Global Navigation Satellite Systems (GNSS) of the US GPS or Russian GLONASS systems. The proposed local maritime Radio VHF Communication, Navigation and Surveillance (CNS) systems and devices, such as Radio Automatic Identification System (R-AIS) or VHF Data Link (VDL), Radio Automatic Dependent Surveillance - Broadcast (RADS-B) and GNSS Augmentation VDL-Broadcast (GAVDL-B) are introduced. The new technology deigns of global Satellite CNS maritime equipment and systems, such as Global Ship Tracking (GST) as enhanced Long Range Identification and Tracking (LRIT), Satellite AIS (S-AIS), Satellite Data Link (SDL), Satellite Automatic Dependent Surveillance - Broadcast (SADS-B) and GNSS Augmentation SDL (GASDL) are discussed and benefits of these new technologies and solution for improved Ship Traffic Control (STC) and Management (STM) are explored. The regional maritime CNS solutions via Stratospheric Communication Platforms (SCP), tracking of ships at sea via Space Synthetic Aperture Radar (SSAR) or Inverse Synthetic Aperture Radar (ISAR)and Ground Synthetic Aperture Radar (GSAR) are described. The special tracking systems for collision avoidance with enhanced safety and security at sea including solutions of captured ships by pirates through aids of the MMSC, SCP and Radars are introduced and the testing methodologies employed to qualify embedded hardware for this environment are presented. During the voyage of the ship in good weather conditions and when navigation devices on the bridge are in order, then can be used very well AIS, LRIT, anti-collision Radar and other on-board equipment. However, at very bad weather conditions sometimes surveillance Radar and Radio HF Transceiver cannot work, but may work only GPS Receiver and L/C-band Satellite Transceiver, while Radio VHF Transceiver will have extremely reduced coverage, what is not enough for safe navigation and collision avoidance. Therefore, during those critical circumstances, when the safety of navigations very important, it will be not necessary to ask "Where am I", but "Where are nearby ships around me"? At this point, it should be needed the newest techniques and equipment for enhanced STC and STM, such as GST, S-AIS, SDL, SADS-B and GASDL. Terrorists exploit surprise in successful pirate actions worldwide and security forces are generally unaware of the source of these attacks at sea. In today’s information age, terror threats may originate with transnational organizations or exploit the territory of failed, weak or neutral states. Thus, countering piracy by eliminating the terrorists on land is the best solution, however, it might not be feasible and even though it’s successful could require many years. In the thesis, the general overview of Radio and Mobile Satellite Systems (MSS) for ship communication and tracking systems is conducted as well, including the space platform and orbital mechanics, horizon and geographic satellite coordinates and classification of spacecraft by Geostationary Earth Orbits (GEO) and Non-GEO orbits.
259

Ecodriving - hot eller möjlighet : En kvalitativ studie om intresset för ecodriving till sjöss

Jakobsson, Niklas, Rydholm, Peter January 2017 (has links)
Det finns ekonomiska, säkerhetsmässiga och miljömässiga vinster att göra genom att tillämpa ecodriving. Tidigare forskning pekar på att transportslagen bilar, tåg och flyg har gjort stora besparingar i ekonomiskt och miljömässigt hänseende, men hur ser det ut inom sjöfarten? Med denna frågeställning som bakgrund är syftet med studien att studera intresset för ecodriving bland svenska rederier och svenska myndigheter med en fartygsflotta. Dataunderlaget för studien utgörs av material från kvalitativa intervjuer med personer i exekutiv position. Resultatet av studien visar på att de flesta verksamheterna står i startgroparna eller redan arbetar utifrån en eller flera aktivt valda metoder för ecodriving. Resultatet visar också att det finns en blandning av förutsättningar och uppfattningar om vad ecodriving är och vad det kan bli inom sjöfarten. När frågor om automatisering i samband med ecodriving behandlas är resultatet tvetydigt. / There are economical, safetylike and environmental benefits of applying eco-driving. Previous research has shown that cars, trains and aviation have made significant savings economically and environmentaly speaking, but how does that transcend into the maritime business? With this question as a background, the aim with this thesis is to examine the interest of ecodriving among Swedish shipowners and authorities. The data in this thesis is derived from qualitative interviews with employees in executive land-based positions. The result shows that several of the shipowners and authorities are in the starting pits or are already conducting one or more eco-driving methods in their operations. The result also shows that there is a variety of prerequisites and perceptions of what eco-driving is and what is could become in the future among the respondents. When questions about automatization in relation to eco-driving are brought up, the result is ambiguous.
260

Maritime shipping container security and the Defense Transportation System: problems and policy in the 21st century

Jankowski, William M. 06 1900 (has links)
Approved for public release, distribution is unlimited / The Defense Transportation System (DTS), led by the Military Traffic Management Command (MTMC), depends on the commercial maritime industry to provide movement of supplies and equipment around the world. The maritime shipping container is a critical asset in providing for this logistical support to the war fighter abroad. These 20- or 40-foot containers have become the backbone of the maritime industry, and will continue to proliferate as global commerce continues to expand. While the growth in the use of maritime shipping containers in the 21st century has accelerated the nation's economic trade substantially, it may also have become a significant problem. Containers are an indispensable but vulnerable link in the chain of global trade; approximately 90 percent of the world's cargo moves by container. Because of DoD's dependency on the maritime industry and these containers, it will and must continue to ride the wave of commercial practices, specifically in pursuit of better security throughout the maritime industry. In the wake of September 11, 2001, and with the new threats of WMD, the maritime shipping container may become a weapons delivery system. This thesis documented the need for security improvements for the maritime shipping container in protecting global commerce and DoD cargo shipments. Comprehensive reviews of government reports, books, articles, and Internet based materials, as well as interviews with MTMC personnel, have indicated that DoD is taking a series of measures to meet these challenges. DoD's Defense Transportation System and the commercial maritime industry will be challenged and tested by new policy requirements. MTMC has already adopted new business processes, cargo manifest requirements, and technological innovations that assure customers in-transit visibility and total asset visibility (ITV/TAV), including the Intelligent Road-Rail Information Server (IRRIS) system. / Lieutenant Commander, United States Navy

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