Consumer valuation of energy-saving features of residential air conditioners with hedonic and choice models

The promotion of energy-efficient appliances is necessary to reduce the energetic and environmental burden of the household sector. However, many studies have reported that a typical consumer underestimates the benefits of energy-saving investment on the purchase of household electric appliances. To analyze this energy-efficiency gap problem, many scholars have estimated implicit discount rates that consumers use for energy-consuming durables. Although both hedonic and choice models have been used in previous studies, a comparison between two models has not yet been done. This study uses point of sale data about Japanese residential air conditioners and estimates implicit discounts rates with both hedonic and choice models. Both models demonstrate that a typical consumer underinvests in energy efficiency. Although choice models estimate a lower implicit discount rate than hedonic models, the latter models estimate the values of other product characteristics more consistently than choice models.

Designing features for supporting social interactions in online communities

This Master's thesis studies the development of interaction and socialization in online communities. A large number of online communities fade away even before they really get started. In many occasions the reason is that the community does not give anything new, or even if they do, the delivery does not satisfy the users. In this thesis guidelines were developed to help to see important things, which might be forgotten when developing an online community. The thesis goes through the characteristic of an online community and human behaviour related to them and also compares behaviour in the Internet and real life. In addition, usability is an important part of the online communities and thus it is also covered in this thesis. As a result of this thesis an 8-step guideline was developed to ease the design of an online community. Guidelines were also applied to two real life cases which are described as one part of this work.

Nocturnal Transcutaneous Carbon Dioxide and Early Changes in Atherosclerosis in Pre- and Postmenopausal Women

The risk of cardiovascular diseases and sleep-disordered breathing increases after menopause. This cross-sectional study focuses on overnight transcutaneous carbon dioxide (TcCO₂) measurements and their power to predict changes in the early markers of cardiovascular and metabolic diseases. The endothelial function of the brachial artery, the intima-media thickness of the carotid artery, blood pressure, glycosylated hemoglobin A1C and plasma levels of cholesterols and triglycerides were used as markers of cardiovascular and metabolic diseases. The study subjects consisted of healthy premenopausal women of 46 years of age and postmenopausal women of 56 years of age. From wakefulness to sleep, the TcCO₂ levels increased more in postmenopausal women than in premenopausal women. In estrogen-users the increase in TcCO₂ levels was even more pronounced than in other postmenopausal women. From the dynamic behaviour of the nocturnal TcCO₂ signal, several important features were detected. These TcCO₂ features had a remarkable role in the prediction of endothelial dysfunction and thickening of the carotid wall in healthy premenopausal women. In addition, these TcCO₂ features were linked with blood pressure, lipid profile and glucose balance in postmenopausal women. The nocturnal TcCO₂ profile seems to contain significant information, which is associated with early changes in cardiovascular diseases in middle-aged women. TcCO₂ might not only measure the tissue carbon dioxide levels, but the TcCO₂ signal variation may also reflect peripheral vasodynamic events caused by increased sympathetic activity during sleep.

Knowledge Sharing in a Virtual Learning Community

The focus of this Master’s Thesis is on knowledge sharing in a virtual Learning community. The theoretical part of this study aims at presenting the theory of knowledge sharing, competence development and learning in virtual teams. The features of successful learning organizations as well as enablers of effective knowledge sharing in virtual communities are also introduced to the reader in the theoretical framework. The empirical research for this study was realized in a global ICT company, specifically in its Human Resources business unit. The research consisted of two rounds of online questionnaires, which were conducted among all the members of the virtual Learning community. The research aim was to find shared opinions concerning the features of a successful virtual Learning community. The analysis of the data in this study was conducted using a qualitative research methodology. The empirical research showed that the main important features of a successful virtual Learning community are members’ passion towards the community way of working as well as the relevance of the content in the virtual community. In general, it was found that knowledge sharing and competence development are important matters in dynamic organizations as well as virtual communities as method and tool for sharing knowledge and hence increasing both individual and organizational knowledge. This is proved by theoretical and by empirical research in this study.