A SOLUTION ALGORITHM FOR p-MEDIAN LOCATION PROBLEM ON UNCERTAIN RANDOM NETWORKS

This paper investigatesthe classical $p$-median location problem in a network in which some of the vertex weights and the distances between vertices are uncertain and while others are random. For solving the $p$-median problem in an uncertain random network, an optimization model based on the chance theory is proposed first and then an algorithm is presented to find the $p$-median. Finally, a numerical example is given to illustrate the efficiency of the proposed metho

Late Precontact and Protocontact Stone Circle Sites at Little Manitou Lake, South-Central Saskatchewan

This study focuses on the Little Manitou Lake archaeological complex, a collection of sites situated around the western end of Little Manitou Lake, located in south-central Saskatchewan. The majority of sites documented in this region contain stone circle features suggesting residential/domestic use while a handful of sites have been documented as ceremonial in nature, containing medicine wheels and vision quest features. Today, Little Manitou Lake is hypersaline and has been so for the last 2,000 years. Evidence suggests that the lake was previously a deep freshwater lake. Changing climatic and environmental conditions responsible for the transformation of the lake would likely have influenced lifeways of past populations and may have influenced use of this area. Archaeological sites around Little Manitou Lake have been hypothesized to relate to the saline/healing nature of the water. The named Manitou comes from an Algonquian word meaning “great spirit” and the lake became known as the “Lake of Healing Waters”. Ethnographic information indicates that aboriginal groups made pilgrimages to the lake to experience the lakes healing properties. The main objective of this research was to improve understanding of interactions between past populations and the environment of the Little Manitou Lake area and to set the local archaeological record into the broader context of Northern Plains prehistory. The importance of this area to past populations is demonstrated by the density of archaeological sites identified around the lake. Considering paleoenvironmental data in relation to these sites provides new insights about human-environment interactions and how changing environmental conditions may have influenced past use of this area. To achieve the objective of this study, three goals were set out and explored: to identify hearth deposits at archaeological sites that could provide dates for site occupation in the area, to review paleoenvironmental data to better understand changing water and salinity levels of the lake through time, and to carry out spatial analyses to evaluate how site placement may relate and help elucidate the overall cultural landscape. Hearth deposits, containing charred organics, were identified which produced dates for three archaeological sites, establishing part of the cultural chronology for the region and provided data which suggest occupation occurred during the late summer or early autumn. The sites were found to belong to the Precontact and Protocontact periods. Data from EkNk-3 indicated that occupation occurred during a period of transition from the Late Old Women’s phase to the Mortlach phase while data from EkNj-4 and EkNj-68 indicated that occupations occurred during the Mortlach phase. Dates from these sites, when compared to the literature relating to paleoenvironmental conditions in the region, allowed for the inference that Little Manitou Lake was a saline lake during site occupation, leading to an improved understanding of the environmental context in which the sites were utilized. Spatial analyses were conducted on both domestic and ceremonial sites in the area. Spatial evaluations of domestic sites at the western end of Little Manitou Lake provided insight about the patterning of features present at the sites. Spatial evaluations of ceremonial sites provided insight about the importance of prominent topographic features in the region and helped to elucidate the overall cultural landscape. Taken as a whole, data collected during this study provides substantive new insights about the archaeological environment at Little Manitou Lake

Intermediate reading exercises for use with the Durrell Analysis of Reading Difficulty.

Thesis (Ed.M.)--Boston Universit

RESILIENT AND STRUCTURALLY CONTROLLABLE DESIGN OF MULTI-LEVEL INFRASTRUCTURE NETWORKS UNDER DISRUPTIONS

An infrastructure network comprises of different entities that are connected by the flow of materials, products, information or electricity. Disruptions could occur at any section of the network for a wide variety of reasons. Some examples include: company mergers (e.g., Halliburton’s impending purchase of Baker Hughes), labor union strikes (e.g., labor strike on the west coast of the United States in 2002), sanctions imposed or lifted (e.g., economic sanctions against Iran being lifted by the UN in July 2015), plantations being destroyed (banana plantations were destroyed by Hurricane Mitch in 1998), air traffic being suspended due to weather or terrorism, main suppliers put out of commission by natural disasters (e.g., the 1999 earthquake in Taiwan disrupted semiconductor fabrication facilities), etc. A resilient infrastructure network is one that has the ability to recover quickly from disruptions and ensure customers are minimally affected, while the simultaneous design of operational and strategic decisions in all levels of the network structure are considered. It becomes very important to design a resilient multi-level infrastructure network in order to manage disruptions using appropriate pre-disruption and post-disruption restoration strategies. The capability of structural controllability can help in recovering a disrupted infrastructure network and increasing its resilience before, during and after the occurrence of disruptions. In this dissertation, the problem of applying structural controllability in order to design a resilient multi-level infrastructure network under disruptions with the selection of appropriate restoration strategies and consideration of the trade-off between effectiveness and redundancy in the resilience analysis is considered. The aforementioned problem has four aspects worth of consideration: a) multi-level network structures, b) restorations strategies, c) resilience analysis, and d) structural controllability. In this regard, the primary research question is defined as: What methods are required for designing a resilient infrastructure network under disruptions through selecting appropriate restoration strategies in a manner of applying structural controllability? The primary research question is broken into four secondary questions in respect to each four aspects of the considered problem as follows. - What is a method to design a multi-level infrastructure network (e.g., node-level and network-level structures) considering both operational and strategic decisions? - What is a method to design a resilient infrastructure network through selecting appropriate pre-disruption (e.g., facility fortification, backup inventory) and post-disruption (e.g., reconfiguration, flexible production and inventory capacity) restoration strategies? - What is a method to evaluate network resilience as a function of time considering effectiveness and redundancy measures (e.g., service level and transportation time as effectiveness measures and control cost as redundancy measure)? - What is a method to determine the minimum number of driver nodes (i.e., driver nodes or controllers are required for controlling networks) to get structurally controllable infrastructure networks? In response to the primary research question, two methods are proposed in this dissertation. The first method is the multi-level infrastructure network (MLIN) method which refers to the first aspect of the problem. The second method is the resilient and structurally controllable infrastructure network (RCIN) method which refers to the second, third and last aspects of the problem. Based on these two proposed methods, the main created new knowledge in this dissertation is in tailoring and incorporating the structural controllability theory in the resilience analysis of disrupted infrastructure networks. The proposed MLIN and RCIN methods are verified and validated using two examples from the energy industry in the context of the validation square. An example of a network of electric charging stations for plug-in hybrid electric vehicles using renewable energy and power grid as sources of energy is used to demonstrate and validate the MLIN method. An example of a network of a multi-product European petroleum industry is used to demonstrate and validate the RCIN method. Although the proposed methods are solved for the two examples, both of them are generalizable to be applicable to any network-based complex engineered systems under disruptions