Reconstruction of cranial bone defects with fiber-reinforced composite–bioactive glass implants

A cranial bone defect may result after an operative treatment of trauma, infection, vascular insult, or tumor. New biomaterials for cranial bone defect reconstructions are needed for example to mimic the biomechanical properties and structure of cranial bone. A novel glass fiber-reinforced composite implant with bioactive glass particulates (FRC–BG, fiber-reinforced composite–bioactive glass) has osteointegrative potential in a preclinical setting. The aim of the first and second study was to investigate the functionality of a FRC–BG implant in the reconstruction of cranial bone defects. During the years 2007–2014, a prospective clinical trial was conducted in two tertiary level academic institutions (Turku University Hospital and Oulu University Hospital) to evaluate the treatment outcome in 35 patients that underwent a FRC–BG cranioplasty. The treatment outcome was good both in adult and pediatric patients. A number of conventional complications related to cranioplasty were observed. In the third study, a retrospective outcome evaluation of 100 cranioplasty procedures performed in Turku University Hospital between years 2002–2012 was conducted. The experimental fourth study was conducted to test the load-bearing capacity and fracture behavior of FRC–BG implants under static loading. The interconnective bars in the implant structure markedly increased the load-bearing capacity of the implant. A loading test did not demonstrate any protrusions of glass fibers or fiber cut. The fracture type was buckling and delamination. In this study, a postoperative complication requiring a reoperation or removal of the cranioplasty material was observed in one out of five cranioplasty patients. The treatment outcomes of cranioplasty performed with different synthetic materials did not show significant difference when compared with autograft. The FRC–BG implant was demonstrated to be safe and biocompatible biomaterial for large cranial bone defect reconstructions in adult and pediatric patients.

Challenges for virtual teams in voluntary organizations

This research concerns virtual teams in the field of volunteer work. The developments in the area of information and communication technology have decreased their costs and made them easily accessible. As a result, it seems natural that also the voluntary organizations have adopted online tools and virtual teams as a part of their work modes. However, virtual teams have not received much research in this context, and one of the goals of this study was to begin closing that gap. The research had two main focus areas: the challenges that the volunteers face in the teams, and the leadership that the teams have. The study used a qualitative approach and semi-structured interviews. The interviews were conducted over Skype and email and included members from six different teams. The case organization was a European-wide student organization that widely utilized virtual teams in its work. The study identified three critical issues for managing the virtual teams. The first challenge was creating common ground for teamwork through electronic communication. Secondly, volunteering created challenges for the teams through variations in the level of commitment of the members, as some left the organization during the term of the team. Lastly, knowledge transfer was a challenge that came from changing the team members regularly each year. As for the second key topic, leadership in the teams was spread among the team members unevenly. The teams had a formal leader, but they exhibited signs of shared leadership, and the team members were able to influence the team through their own level of involvement. Especially the experience that a member had contributed the amount of influence she held. All in all, the challenges that the volunteers faced were similar to those of normal virtual teams. Volunteering brought additional challenges through the varying levels of commitment and the changing of the team members. Additionally, the role of the team leader was not as firm. The results of the study can be applied to other volunteer organizations that utilize virtual teams.

Challenges for virtual teams in voluntary organizations

This research concerns virtual teams in the field of volunteer work. The developments in the area of information and communication technology have decreased their costs and made them easily accessible. As a result, it seems natural that also the voluntary organizations have adopted online tools and virtual teams as a part of their work modes. However, virtual teams have not received much research in this context, and one of the goals of this study was to begin closing that gap. The research had two main focus areas: the challenges that the volunteers face in the teams, and the leadership that the teams have. The study used a qualitative approach and semi-structured interviews. The interviews were conducted over Skype and email and included members from six different teams. The case organization was a European-wide student organization that widely utilized virtual teams in its work. The study identified three critical issues for managing the virtual teams. The first challenge was creating common ground for teamwork through electronic communication. Secondly, volunteering created challenges for the teams through variations in the level of commitment of the members, as some left the organization during the term of the team. Lastly, knowledge transfer was a challenge that came from changing the team members regularly each year. As for the second key topic, leadership in the teams was spread among the team members unevenly. The teams had a formal leader, but they exhibited signs of shared leadership, and the team members were able to influence the team through their own level of involvement. Especially the experience that a member had contributed the amount of influence she held. All in all, the challenges that the volunteers faced were similar to those of normal virtual teams. Volunteering brought additional challenges through the varying levels of commitment and the changing of the team members. Additionally, the role of the team leader was not as firm. The results of the study can be applied to other volunteer organizations that utilize virtual teams.

Computational Market Dynamics of Virtual Economies

The last two decades have provided a vast opportunity to live and explore the compulsive imaginary world or virtual world through massively multiplayer online role-playing games (MMORPGs). MMORPG gives a wide range of opportunities to its users to participate with multi-players on the same platform, to communicate and to do real time actions. There is a virtual economy in these games which is largely player-driven. In-game currency provides its users to build up their Avatars, to buy or sell the necessary goods to play, survive in the games and so on. As a part of virtual economies generated through EVE Online, this thesis mainly focuses on how the prices of the minerals in EVE Online behave by applying the Jabłonska- Capasso-Morale (JCM) mathematical simulation model. It is to verify up to what degree the model can reproduce the virtual economy behavior. The model is applied to buy and sell prices of two minerals namely, isogen and morphite. The simulation results demonstrate that JCM model ts reasonably well to the mineral prices, which lets us conclude that virtual economies behave similarly to the real ones.

Exploring knowledge worker motivation in autonomous and interdependent problem solving tasks on virtual platforms

The objective of this study is to understand why virtual knowledge workers conduct autonomous tasks and interdependent problem solving tasks on virtual platforms. The study is qualitative case study including three case organizations that tap the knowledge of expert networks, and utilize virtual platforms in the work processes. Research data includes 15 interviews, that is, five experts from each case company. According to the findings there are some specific characteristics in motivation to work on tasks on online platforms. Autonomy, self-improvement, meaningful tasks, knowledge sharing, time management, variety of contacts, and variety of tasks, and projects motivate virtual knowledge workers. Factors that may enhance individuals’ engagement to work on tasks are trust, security of continuous task flow and income, feedback, meaningful tasks and tasks that contribute to self-improvement, flexibility and effectiveness in time management, and virtual tools that support social interaction. The results also indicate that there are some differences in individuals’ motivation based on the tasks’ nature. That is, knowledge sharing and variety of contacts motivated experts who worked on interdependent problem solving tasks. Then again, autonomy and variety of tasks motivated experts who worked on autonomous tasks.

Co-creating Value For Smart Phone Operating Systems Via Virtual Discussion Forums

In the traditional way, value is created by manufacturer or producer of a product without engaging the customers. So, traditionally value creation is a monopoly in the part of a manufacturer. After gathering all the raw materials the manufacturers are inserting value to a product. And the inserted value is recognized in the time of consuming the product. In the modern time though there is traditional way of value creation but with the increase of more educated, smart, and technically sound customers the idea of value creation has changed. Now, customers are also contributing in value creation as value co-creator even before the product is consumed. This scenario has been encountered in the thesis with the main purpose of how value is cocreated in smart phone operating systems. The purpose is further divided into the following supobjectives: o What is value co-creation in smart phone operating systems? o Who participates in value co-creation in smart phone operating systems? o What are the procedures that are involved in value co-creation in smart phone operating systems? The research was conducted as a qualitative desk study by observing two of the leading smart phone operating system providers. Data has been collected from the official discussion forum of both the operating system providers. Other general concepts relating to the purpose of the study has been encountered through literature review. The research findings reveal that customers and companies both together co-create value of anticipated level when they communicate and interact with each other. However, most of the time customer to customer interactions, dialogues and discussions that come out in the core conversation help the value co-creation. The value co-creation framework sets up the customer at the main focus of value creation theory. By nullifying the inherited notion that companies only create value within its boundary and provide it to their customers in exchange of currencies. Rationally, it has been commenced that the firms are merely compromising value propositions to its customers. But the value has been co-created in a point where offerings are combined and interacted with customers’ capabilities, knowledge, resources and perceptions. This new perspective has radically altered the prospect of firms towards its customers. Typically customers are now taking part in value cocreation as a crucial member.

Spectral Retinal Images Reconstruction

While red-green-blue (RGB) image of retina has quite limited information, retinal multispectral images provide both spatial and spectral information which could enhance the capability of exploring the eye-related problems in their early stages. In this thesis, two learning-based algorithms for reconstructing of spectral retinal images from the RGB images are developed by a two-step manner. First, related previous techniques are reviewed and studied. Then, the most suitable methods are enhanced and combined to have new algorithms for the reconstruction of spectral retinal images. The proposed approaches are based on radial basis function network to learn a mapping from tristimulus colour space to multi-spectral space. The resemblance level of reproduced spectral images and original images is estimated using spectral distance metrics spectral angle mapper, spectral correlation mapper, and spectral information divergence, which show a promising result from the suggested algorithms.