Detta arbete undersöker migration från legacy-system till en molnbaserad miljö. Legacy-system är ett system som byggts upp under organisationens livstid och är kritiskt för attverksamheten ska fungera. Syftet med arbetet är att undersöka vilka motiverande ochutmanande faktorer som påverkar denna migration och hur dessa faktorer påverkartillvägagångssätt och de beslut som fattas. Den teoretiska bakgrunden bygger på tidigarestudier av legacy till moln-migration, där ett antal faktorer identifieras som viktiga. Därtillbeskrivs fyra områden som är centrala för tillvägagångssättet i denna typ av migration, blandannat arkitektur, val av destination och fyra migrationstyper. Kvalitativa intervjuer hargenomförts för att bidra till en fallstudie av ett stort företag som just nu genomför enmolnmigration. Tillsammans med tillgängligt material har intervjuerna analyserats ochresulterat i en diskussion där vi för vissa faktorer kunnat bekräfta deras påverkan, samtidentifiera ett antal nya. Slutligen visar vi på hur dessa faktorer har påverkat beslut som detundersökta företaget fattat under processen och vilket tillvägagångssätt dessa lett till. Därfinner vi bland annat att faktorer kopplade till säkerhet har haft mest omfattande påverkan påde fyra undersökta områdena.

Organizations that have come to depend on legacy systems face quite a paradoxical problem. Maintaining the system might prove ineffective in accommodating necessary changes, but a system migration project is expensive and incurs a high amount of risk. Organizations are therefore hesitant to respond to the legacy system problem by undertaking action. Legacy system are often not causing their organization any problems at present, but a focus on the future with regard to the legacy system problem is lacking. This results in IT systems reaching an end-of-life state. The research therefore set out to explore a future-oriented perspective on legacy systems by means of observation, a literature review and a survey. The researcher found the key concept of a future-oriented perspective to be that any system that is limiting an organization to grow and innovate can be regarded as a legacy system. A framework to designate legacy status to IT systems is proposed in order to guide practitioners to acknowledge a problematic IT system to facilitate appropriate response at the right time. In relation to a future-oriented perspective, when to designate legacy status is best determined according to the system’s flexibility towards change and the alignment of the system with the business. In that regard, IT systems are end-of-life systems when they are too inflexible to change, and as a result become unaligned with either current operations or a future business opportunity or need.

Mining has left many long-lasting effects, often negative. Mining continues to this day and questions persist; “what are the legacies of mining, to what extent do our approval and assessment processes consider these effects, are we learning from our past experiences and how can we amplify our learning?” To answer these questions I interviewed people from the mining community of Snow Lake, Manitoba as well as mining and assessment experts from across Canada. Data collected though document analysis and semi-structured interviews with 24 participants were analyzed using mining legacy, EA, and transformative learning frameworks. Results reinforce a suite of negative legacy effects identified in the literature. EA may be the best tool we currently have for long-term planning but data show it is unable to fully consider legacy effects. Learning is important for moving towards sustainability; however, a community’s economic dependence and mining friendly culture can act as barriers to learning. / May 2016

Thesis advisor: Noah P. Snyder / Centuries-long intensive land use change in the northeastern U.S. provides the opportunity to study the response timescale of geomorphic processes to anthropogenic perturbations. In this region, deforestation and the construction of dams following European settlement drastically altered the landscape, leading to the impoundment of sediment in mill ponds. This legacy sediment continues to be released into transport decades after a dam has been removed or breached. Geochemical tracers can help distinguish sediment sources and understand how sediment moves through a watershed. The South River in western MA is located in a formerly glaciated watershed, and these surficial deposits compose 98% of the area. It experienced two generations of damming, beginning with smaller mill dams in the 18th-19th centuries, followed by the construction of the Conway Electric Dam (CED), a 17 m tall hydroelectric dam in the early 20th century. Legacy sediment deposits from sediment stored behind mill dams cover 1.5% of the watershed area. The CED is located near the outlet of the river, providing a century-long depositional record for the watershed, during reforestation. I hypothesize that sediment mobilized from human activity will contain a different geochemical signature than glacial material, that recent erosion in the watershed is primarily from anthropogenic legacy deposits rather than from glacial age landforms, and channel widening is occurring in reaches of the channel composed of legacy sediment, rather than in glacially confined reaches. These hypotheses were tested through a two part investigation, consisting of a sediment tracing study using Hg, and a Geographic Information Systems (GIS) analysis of channel changes using aerial photographs from 1940 and 2014. Samples were collected from river bank exposures of 11 glacial deposits and four mill pond legacy sites. Two vibracores measuring 476 and 500 cm were collected in reservoir sediment stored behind the CED in 2013 and 2017, respectively. Hg concentrations range from 1-4 ppb in glacial sediment, 3-380 ppb in legacy sediment, and 2-18 ppb and 7-50 ppb in the two CED cores. I used Hg as a tracer to estimate percent contributions to the CED reservoir from each watershed source during the 20th century. Results from a sediment mixing model suggest glacial sources contributed 32 ± 15%, and legacy sediment deposits contributed 68 ± 15% during the 20th century. Based on 137Cs dates on the cores, high amounts of legacy sediment filled in behind the CED prior to 1953 (74 ± 35 %), and background erosion from glacial deposits dominated from 1953 until the reservoir was filled in the 1980s (63 ± 14%). GIS analyses using aerial photographs from 1940 and 2014 indicate that the channel did not significantly widen along any section of the river, however, increases in sinuosity (up to 12%) occurred in the legacy sediment dominated reaches of the channel, and minor increases (1-2%) occurred in the glacial reaches. Overall, these analyses show an increase in the amount of sediment released in the channel as a result of mill dams breaching through the mid-19th to early 20th centuries, and suggest a short recovery timescale response from this land-use change. / Thesis (MS) — Boston College, 2018. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

Thesis advisor: Noah P. Snyder / Large-scale human modification of the northeastern U.S. landscape began in the 17th century with forest clearing and milldam construction. In the mid-Atlantic Piedmont region of the U.S., Walter and Merritts (2008) found that millpond deposits persist for centuries after dam breaching, resulting in fill terraces composed of legacy sediment. Stratigraphic observations in the mid-Atlantic indicate that these laminated to massive fine-grained layers typically overly a prominent Holocene hydric soil that overlies a Pleistocene basal gravel. I test whether this set of processes applies to glaciated New England. This study focuses on two New England watersheds: the South River in Massachusetts and the Sheepscot River in Maine. I use stratigraphic analysis and radiocarbon dating to identify legacy deposits, and then use lidar digital elevation models to map planar terrace extents in each watershed. Finally, I use lidar digital elevation models to estimate thickness of legacy sediment found behind breached or removed milldams and estimate volumes of legacy sediment storage in valley bottoms over entire watersheds. The South River watershed has 32 historic dam sites; 18 have been field checked and 14 show evidence for legacy sediment storage. The Sheepscot River watershed has 33 historic dam sites; 13 have been field checked and six show evidence of legacy sediment storage. Stratigraphic analyses of bank exposures in both watersheds show a brown fine sand and silt layer (up to 2.19 m thick in the South River watershed and up to 2.30 m thick in the Sheepscot River watershed) which sometimes is underlain by gravel and/or clay; no buried Holocene hydric soil has been found. Further evidence for legacy milldam sedimentation comes from radiocarbon dating. Three radiocarbon dates from the South River watershed and six from the Sheepscot River watershed are less than 300 years old; no underlying Holocene material has been dated. The maximum volume of legacy sediment estimated using lidar methods for the South River watershed is 2.5 x 106 m3 and for the Sheepscot River watershed the volume is 3.7 x 106 m3. These volumes of legacy sediment can be translated to maximum mean thickness of sediment eroded from each landscape: 37 mm for the South River watershed and 7 mm for the Sheepscot River watershed. The Sheepscot River watershed has most of its legacy sediment terraces in the lower section of the watershed with many lakes and wetlands disturbing sediment transport in the upper section of the watershed. Compared to the Sheepscot River watershed, the South River watershed has more widespread glacial deposits contributing to legacy sediment with few lakes and wetlands. / Thesis (MS) — Boston College, 2017. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

Thesis advisor: Noah Snyder / While it has been shown that extensive sedimentation in historic millponds has greatly affected streams in the Mid-Atlantic Piedmont region (Walter and Merritts, 2008), much less is known about the phenomenon in the heavily dammed areas of post-glacial New England. Some research has found similar deposits behind breached historic dams in the Sheepscot River watershed in mid-coast Maine, but at a smaller scale than those seen in the Mid-Atlantic region (Strouse, 2013; Hopkins, 2014). I attempt to further explore millpond sedimentation in New England by quantifying the volume of millpond sediment, also called legacy sediment, in the 171.3 km² upper Charles River watershed in eastern Massachusetts. Twenty three milldams were located in the watershed on 1850s maps, giving a damming density of 0.177 dams/km². Each historic dam that had since breached, 14 in total, was visited in the field to identify possible legacy sediment deposits. Legacy sediments were identified by their meter or higher terraces made of fine sands and silt and verified by comparison to sedimentary patterns found in other legacy sediment deposits and radiocarbon dating of material both within the legacy sediment and in the underlying layer. Legacy sediment terraces with an area of 1.68*10⁴ m² and a total volume of 1.29 - 2.57*10⁴ m³ were found upstream of two adjacent breached historic dam sites on the Charles River in Medway, MA. Radiocarbon dates from a coarse sand and gravel lower at 1.8 m depth returned pre-settlement dates of 1281-1391 cal AD (two σ). These dams were immediately downstream of a large glacial feature with steep banks along the river. The lack of legacy sediment at other dam sites and the lack of sedimentation behind intact dams suggest that a low sediment supply to millponds prevented legacy sediment deposits from forming in most of the watershed. / Thesis (BS) — Boston College, 2016. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Earth and Environmental Sciences.

It is incumbent upon teachers to reach out to students through methods that capitalize on the students' own motivations. Because of the diversity of self-referential personal styles of learning, reaching every student with a cookie-cutter approach to teaching is nearly impossible. This report explores the application of a type of problem-based learning known as "Legacy Cycles" that apply web technology to answer challenges presented as scenarios. The scenarios give students a similar experience to scientists pursuing investigation and research. Students then search for answers to questions, learn more about the processes being taught with hands-on activities, and prepare a product to demonstrate mastery of the content. In this example of the Legacy Cycle, three challenges are used to teach concepts of density, ocean currents and plastic pollution. / text

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The NASA Space Network (SN), which consists of the geosynchronous Tracking and Data Relay Satellite (TDRS) constellation and its associated ground elements, is a critical national space asset that provides near-continuous, high-bandwidth telemetry, command, and communications services for numerous spacecraft and launch vehicles. The Space Network includes several key ground system elements, one of which is the White Sands Complex Data Interface Service Capability (WDISC). The WDISC has undergone multiple cycles of modification and technology refresh over its lifetime, making test automation an attractive option for reducing system verification and validation cost. This paper considers the implementation of automated testing for the WDISC as a case study in technology sustainment, discusses the principal benefits and challenges of implementing test automation for a legacy system, and presents findings that demonstrate the effectiveness of such automation models.

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