On the Adoption Dynamics of Internet Technologies: Models and Case Studies

Today, more than any time in history, our life-styles depend on networked systems, ranging from power grids to the Internet and social networks. From shopping online to attending a conference via P2P technologies, the Internet is changing the way we perform certain tasks, which incentivizes more users to join the network. This user population growth as well as higher demand for a better access to the Internet call for its expansion and development, and therefore, fuel the emergence of new Internet technologies. However, many such technologies fail to get adopted by their target user population due to various technical or socio-economical problems. Understanding these (adoption) problems and the factors that play a significant role in them, not only gives researchers a better insight into the dynamics of Internet technology adoption, but also provides them with enhanced guidelines for designing new Internet technologies. The primary motivation of this thesis is, therefore, to provide researchers and network technology developers with an insight into what factors are responsible for, or at least correlated with, the success or failure of an Internet technology. We start by delving deeply into (arguably) the salient adoption problem the Internet has faced in its 40+ years of existence, and continues to face for at least a foreseeable future, namely, IPv6 adoption. The study is composed of an extensive measurement component, in addition to models that capture the roles of different Internet stakeholders in the adoption of IPv6. Then, we extend it to a broad set of Internet protocols, and investigate the factors that affect their adoptions. The findings show performance as the primary factor that not only affected the adoption of IPv6, but also plays a role in the adoption of any other network data plane protocol. Moreover, they show how backward compatibility as well as other factors can affect the adoption of various protocols. The study provides a number of models and methodologies that can be extended to other similar problems in various research areas, such as network technology adoption and design, two-sided markets, and network economics

Migrating to IPv6 - The Role of Basic Coordination

The need for a larger Internet address space was acknowledged early on, and a solution (IPv6) standardized years ago. Its adoption has, however, been anything but easy and still faces significant challenges. The situation begs the questions of why has it been so difficult? and what could have been (or still be) done to facilitate this migration? There has been significant recent interest in those questions, and the paper builds on a line of work based on technology adoption models to explore them. The results confirm the impact of several known factors, but also provide new insight. In particular, they highlight the destabilizing effect of Internet Service Providers (ISPs) offering competing alternatives (to IPv6), and demonstrate the benefits of even minimum coordination among them in offering IPv6 as an option. The findings afford additional visibility into what affects technology transition in large systems with complex dependencies such as the Internet

Migrating the Internet to IPv6: An Exploration of the When and Why

The paper documents and to some extent elucidates the progress of IPv6 across major Internet stakeholders since its introduction in the mid 90’s. IPv6 offered an early solution to a well-understood and well-documented problem IPv4 was expected to encounter. In spite of early standardization and awareness of the issue, the Internet’s march to IPv6 has been anything but smooth, even if recent data point to an improvement. The paper documents this progression for several key Internet stakeholders using available measurement data, and identifies changes in the IPv6 ecosystem that may be in part responsible for how it has unfolded. The paper also develops a stylized model of IPv6 adoption across those stakeholders, and validates its qualitative predictive ability by comparing it to measurement data

Micro- and nanoengineering approaches to control stem cell-biomaterial interactions.

As our population ages, there is a greater need for a suitable supply of engineered tissues to address a range of debilitating ailments. Stem cell based therapies are envisioned to meet this emerging need. Despite significant progress in controlling stem cell differentiation, it is still difficult to engineer human tissue constructs for transplantation. Recent advances in micro- and nanofabrication techniques have enabled the design of more biomimetic biomaterials that may be used to direct the fate of stem cells. These biomaterials could have a significant impact on the next generation of stem cell based therapies. Here, we highlight the recent progress made by micro- and nanoengineering techniques in the biomaterials field in the context of directing stem cell differentiation. Particular attention is given to the effect of surface topography, chemistry, mechanics and micro- and nanopatterns on the differentiation of embryonic, mesenchymal and neural stem cells

Assessing IPv6 Through Web Access - A Measurement Study and Its Findings

Transitioning an infrastructure the size of the Internet is no small feat. We are in the midst of such a transition, \ie from IPv4 to IPv6. IPv6 was standardized 15~years ago, but until recently there were few incentives to adopt it. The allocation of the last large block of IPv4 addresses changed that, and migrating to an IPv6 Internet has become more urgent. This migration is, however, still rife with uncertainties and challenges. The goal of this paper is to provide insight into this transition, and possibly make it smoother. The focus is on the ``network,\u27\u27 and the paper reports on extensive measurements that compare and contrast IPv6 and IPv4. Two important hypotheses, denoted as H1 and H2, were identified and validated. H1 argues that the IPv6 and IPv4 data planes now perform by and large comparably. In contrast, H2 points to routing differences as the primary culprit behind occurrences of poorer IPv6 performance. In other words, promoting IPv6 and IPv4 peering parity is probably the single most effective step towards equal IPv6 and IPv4 performanc

A Comparative Study of Energy Use and Greenhouse Gas Emissions of Canola Production

I n this research, the energy flow and production energy indices of canola cultivation in Trakya province of Turkey, Golestan and Mazandaran provinces of Iran were compared. Diesel fuel and chemical fertilizer inputs were the highest consumer of energy in the production of canola in these three regions. The results indicated that despite the higher energy use of machinery in Trakya province of Turkey, the energy use of diesel fuel in this province is less than the energy consumed in the two northern provinces of Iran, which could be due to available old machines for the production of canola in Mazandaran and Golestan provinces. Total greenhouse gas emissions of canola production for these regions were computed 562.85, 652.86 and 887.30 kgCO 2eq ha-1, respectively. The inputs of chemical fertilizer and diesel fuel in canola production produced the highest percentage of gas emissions in these three areas. Energy consumption for potential feedstock production for one kg production of biodiesel fuel in these provinces was calculated as 14.76, 20.66 and 37.77 MJ, respectively. The amounts of greenhouse gas emissions for potential feedstock production for one kg production of biodiesel were obtained 0.45, 0.76 and 1.17 kgCO 2eq for Trakya, Golestan and Mazandaran provinces, respectively

Micro- and Nanoengineering Approaches to Control Stem Cell-Biomaterial Interactions

As our population ages, there is a greater need for a suitable supply of engineered tissues to address a range of debilitating ailments. Stem cell based therapies are envisioned to meet this emerging need. Despite significant progress in controlling stem cell differentiation, it is still difficult to engineer human tissue constructs for transplantation. Recent advances in micro- and nanofabrication techniques have enabled the design of more biomimetic biomaterials that may be used to direct the fate of stem cells. These biomaterials could have a significant impact on the next generation of stem cell based therapies. Here, we highlight the recent progress made by micro- and nanoengineering techniques in the biomaterials field in the context of directing stem cell differentiation. Particular attention is given to the effect of surface topography, chemistry, mechanics and micro- and nanopatterns on the differentiation of embryonic, mesenchymal and neural stem cells

A Comparative Study of Energy Use and Greenhouse Gas Emissions of Canola Production

I n this research, the energy flow and production energy indices of canola cultivation in Trakya province of Turkey, Golestan and Mazandaran provinces of Iran were compared. Diesel fuel and chemical fertilizer inputs were the highest consumer of energy in the production of canola in these three regions. The results indicated that despite the higher energy use of machinery in Trakya province of Turkey, the energy use of diesel fuel in this province is less than the energy consumed in the two northern provinces of Iran, which could be due to available old machines for the production of canola in Mazandaran and Golestan provinces. Total greenhouse gas emissions of canola production for these regions were computed 562.85, 652.86 and 887.30 kgCO2eq ha -1 , respectively. The inputs of chemical fertilizer and diesel fuel in canola production produced the highest percentage of gas emissions in these three areas. Energy consumption for potential feedstock production for one kg production of biodiesel fuel in these provinces was calculated as 14.76, 20.66 and 37.77 MJ, respectively. The amounts of greenhouse gas emissions for potential feedstock production for one kg production of biodiesel were obtained 0.45, 0.76 and 1.17 kgCO2eq for Trakya, Golestan and Mazandaran provinces, respectively. Abstract International Journal of Agricultural Management and Development (IJAMAD