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

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

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

The Physical and Cultural Background

The Sunken Village wet site (35MU4) is on one of the most important river junctures on the Northwest Coast of North America – where the Columbia River drainage of British Columbia, Canada and Washington State, U.S.A. is joined by the Willamette River flowing through much of western Oregon State, U.S.A. (Figure 2.1). The site is on Sauvie Island, where a major aquifer pumps under the natural levee into Multnomah Channel, providing a unique 125 m wide beach area where acorns placed in shallow hemlock bough-lined pits were leached in huge numbers by ancient Multnomah Peoples (Figure 2.2)

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

Ecofacts – Plant and Animal Analyses

Wet sites, due to reduced oxygen, provide excellent preservation of both plant and animal remains. Due to the clear importance of Sunken Village as an acorn leaching and processing location – largely because of the aquifer streaming through this approximately 100–125 m of intertidal beach – the focus in Section 4 is on the leaching pits and acorn remains. First we begin with a look at identifying the actual plant materials and fuels used at this site, requiring both visual observations of the plant remains and also cellular analysis of the wood, fibers and charcoal. Many of the perishable artifacts are introduced in this section while identifying their wood and fiber construction materials. Second we report the abundant acorns and acorn leaching pit features, so numerous at Sunken Village. Third, seed retrieval is explored, comparing the results of flotation techniques and fine wet screening. And finally, the faunal analysis reflects the use of these animal resources in a secondary position, and probably to support the group while managing the acorn leaching pits from this site. The obvious contrast here to other Northwest Coast and Columbia River sites is the reduced focus on fisheries from this location