Combinaison d'un système de rendez-vous avec le problème d'affectation de ressources dans un terminal à conteneurs

The connection of a container terminal to its hinterland is a key area for competition. Therefore, more and more attention is paid to the service quality of inland transport modes such as trucks, trains and barges. An effcient allocation of internal material handling resources and the use of new strategies, such as truck appointment systems, can reduce the time vehicles spend at the terminal. We propose a mixed integer linear programming model, based on a network flow representation of the terminal, to determine the number of appointments to accept per time slot and an allocation of internal resources minimizing service times of trains and barges simultaneously. By comparing container terminals with and without appointment systems, we show that a truck appointment system is beneficial for trucks as well as for trains and barges

Branch and price approach for the container relocation problem

Container terminals offer transfer facilities to move containers from vessels to trucks, trains and barges and vice versa. Incoming containers are not immediately loaded on an outgoing vehicle, but stored in the yard for up to several days. The yard is divided into blocks with several bays consisting of stacks and tiers. Figure 1 illustrates these terms. Terminals stack containers to use their scare land efficiently. Only the topmost container of each stack can be accessed directly. If another container has to be retrieved, containers above have to be relocated. These unproductive moves cannot be avoided completely as little information about future retrievals is known when a container is stored. But, poor yard management increases the number of relocations and the time needed to retrieve containers. Thereby, it decreases the overall productivity of the terminal. The container (or block) relocation problem consists in minimizing the number of relocations during the retrieval process. The container relocation problem is shown to be NP-hard. We present a branch and price procedure to solve the problem exactly

Affectation optimisée des ressources de déchargement/chargement et de transport dans un terminal à conteneurs multimodal

Nous présentons un programme linéaire mixte pour représenter un terminal à conteneur pour déterminer une affectation de ressources optimisée afin de minimiser les délais des modes de transport terrestre tout en respectant les délais imposés des navires

Toward sustainable supply chains : responding to the challenges and complexities of achieving multi-tier sustainability

Most of today’s supply chains have become more complex and global, consisting of numerous members located in different countries and regions. Thus, distinct challenges in ensuring sustainability arise. This dissertation explores how individual companies and supply chains as a whole can respond to the challenges and complexities of achieving sustainability in global multi-tier supply chains. A computational literature review and two case studies are employed – one case study focusing on the electronics industry and the other on the global agri-food sector. The dissertation provides insights into the latent topical development of the literature on managing sustainability in multi-tier supply chains. It enhances the understanding of potential strategies and concepts, found in the broader body of literature, for addressing the challenges inherent to multi-tier supply chain contexts. In addition, this research adopts a paradox perspective to identify underlying sustainability tensions and related strategies for responding to these specific types of complexities. Moreover, the concept of institutional work is employed to shed light on creating supply chain settings that support the institutionalization of sustainable practices among lower-tier suppliers in challenging country contexts. The findings from this dissertation offer novel theoretical insights and practical implications for achieving multi-tier sustainability in global supply chains. The importance of addressing systemic challenges and complexities through business alliances and other collaborative approaches is highlighted. Furthermore, the need is emphasized for capacity building and appropriate financial rewards to support the adoption of sustainable practices among lower-tier suppliers. Implementing these measures requires the creation of multi-tier supply chain fields that collectively work toward common sustainability goals and the adoption of sustainable practices at lower tiers

Column Generation for the Container Relocation Problem

Container terminals offer transfer facilities to move containers from vessels to trucks, trains and barges and vice versa. Within the terminal the container yard serves as a temporary buffer where incoming containers are piled up in stacks. Only the topmost container of each stack can be accessed. If another container has to be retrieved, containers stored above it must be relocated first. Containers need to be transported to a ship or to trucks in a predefined sequence as fast as possible. Generally, this sequence does not match the stacking order within the yard. Therefore, a sequence of retrieval and relocation movements has to be determined that retrieves containers from the bay in the prescribed order with a minimum number of relocations. This problem is known as the container relocation problem. We apply an exact and a heuristic column generation approach to this problem. First results are very promising since both approaches provide very tight lower bounds on the minimum number of relocations

Seismic Behaviour of Cable-Stayed Bridges: A Review

Cable-stayed bridges represent backbones in the infrastructure networks and their adequate seismic response must be ensured. These structures present complex interactions between the deck, the cables, the towers and their foundation. This, in combination with the reduced damping and the outstanding slenderness of cable-stayed bridges, renders a unique dynamic response. A complete review on the state of knowledge about the seismic behaviour of cable-stayed bridges is presented here, with special attention to the analysis techniques. The current design trends in the seismic design and control of cable-stayed bridges are also presented

Wet-Site Excavation at Sunken Village Site on the Columbia River

The extensive in situ acorn pits are the most remarkable fea­tures at this landmark site. During surface exposure and mapping, all such pits contained remnants of whole acorns. Also wood and fiber artifacts were observed in and around these pits, including a shredded cedar bark cape/skirt fragment, a broken wooden wedge, wooden arrow shafts, and a well-preserved basket distinctive of the region's fine basket work. The basket piece was found with intact base and sides (no rim remained) all carefully cross-warp twined of split cedar root (identified by Bud Lane, master weaver, Siletz, and Patricia Gold, master Wasco weaver, Warm Springs; Figures 5 and 6). The style of this basket is definitely from this region and demonstrates an ancient continuity of this style of basketry. Baskets found from northern ancient wet sites are of a very different style, and themselves demonstrate at least 3,000 years of basketry cultural continuity in Salish, Makah, and Tsimshian traditional territories. For full final report on two summer's of explorations, second one sponsored by Japanese Archaeology program, see: Croes, Dale R., John L. Fagan and Maureen Newman Zehendner 2009 Sunken Village, Sauvie Island, Oregon, USA, A Report on the 2006-2007 Investigations of National Historic Landmark Site 35MU4. Journal of Wetland Archaeology Special Edition 9, 1-216. Available on Amazo

Mangelernährung in der septischen Unfallchirurgie – Hat eine bestehende Mangelernährung einen Einfluss auf das klinische Outcome?

Mangelernährung ist ein durch mangelhafte Nährstoffversorgung verursachter Zustand, der zu einer veränderten Körperzusammensetzung führt. Die Prävalenz der Mangelernährung unter hospitalisierten Patienten aller Fachrichtungen liegt zwischen 16% und 55%. Zahlreiche Studien belegen die negativen Auswirkungen von Mangelernährung auf das klinische Outcome. Es gibt jedoch kaum Untersuchungen zur Mangelernährung in der septischen Unfallchirurgie. In der vorliegenden Studie wurde mit Hilfe des MNA und des NRS die Prävalenz der Mangelernährung in einer Abteilung für septische Unfallchirurgie bestimmt. Die beiden Screeninginstrumente wurden bezüglich ihrer Fähigkeit verglichen, das klinische Outcome zu vorherzusagen. Des Weiteren wurde die Assoziation von Mangelernährung mit möglichen Risikofaktoren untersucht. Die Prävalenz der Mangelernährung lag unter den 345 Studienpatienten bei 31,3% mit dem NRS und 40,8% mit dem MNA. Unter älteren Patienten zeigte sich eine deutlich höhere Prävalenz der Mangelernährung (NRS: 51,6%, MNA: 46,4%). Im Vergleich zu Prävalenzangaben anderer Fachbereiche ist die Prävalenz in der septischen Unfallchirurgie vergleichsweise hoch. Besonders hohe Prävalenzen fanden sich unter Frauen, Patienten mit einem Alter über 60 Jahren, multimorbiden Patienten und Patienten, die auf Hilfe im Alltag angewiesen sind. Patienten mit einem Risiko für eine Mangelernährung nach dem NRS hatten während ihres Aufenthalts signifikant mehr unerwünschte Ereignisse, eine verzögerte physiotherapeutische Mobilisierung, einen längeren stationären Aufenthalt und konnten seltener nach Hause entlassen werden als gut ernährte Patienten. Dahingegen fand sich mit dem MNA lediglich eine Assoziation von Mangelernährung mit einer geringeren Rate an Entlassungen nach Hause. Unter älteren Patienten zeigte sich eine verzögerte physiotherapeutische Mobilisierung mangelernährter Patienten nach dem NRS. Auf Grund der besseren Vorhersage des beeinträchtigten klinischen Outcomes mangelernährter Patienten ist der NRS für die Verwendung der Diagnostik der Mangelernährung in der septischen Unfallchirurgie besser geeignet als der MNA