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In today’s DVB-T/H (Digital Video Broadcasting-Terrestrial/Handheld) systems, broadcasting is employed, meaning that TV programs are sent over all transmitters, also where there are no viewers. This is inefficient utilization of spectrum and transmitter equipment. IP multicasting is increasingly used for IP-TV over fixed broadband access. In this thesis, IP multicasting is proposed to also be used for terrestrial and mobile TV, meaning that TV programs are only transmitted where viewers have sent join messages over an interaction channel. This would substantially improve the system spectral efficiency (SSE) in (bit/s)/Hz/site, allowing reduced spectrum for the same amount of TV programs. It would even further improve the multiuser system spectral efficiency (MSSE – a measure defined in this study), allowing increased number of TV programs to be transmitted over a given spectrum. Further efficiency or coverage improvement, may be achieved by forming single-frequency networks (SFN), i.e. groups of adjacent transmitters sending the same signal simultaneously, on the same carrier frequency. The combination of multicasting and SFNs is also the principle of eMBMS (evolved Multicast Broadcast Multimedia Service) for cellular mobile TV over 4G LTE. PARPS (packet and resource plan scheduling) is an optimized approach to dynamically forming SFNs that is employed in this study. The target applications are DVB-T/H and eMBMS. Combining SFNs with non-continuous transmission (switching transmitters on and off dynamically) may give even further gain, and is used in LTE, but is difficult to achieve in DVB-T/H. Seven schemes are suggested and analyzed, in view to compare unicasting, multicasting and broadcasting, with or without SFN, with or without PARPS, and with or without continuous transmission. The schemes are evaluated in terms of coverage probability, SSE and MSSE. The schemes are simulated in MATLAB for a system of 4 transmitters, with random viewer positions. Zipf-law TV program selection is employed, using both a homogeneous and heterogeneous user behavior model. The SFN schemes provide substantially better system spectral efficiency compared to the multi-frequency networks (MFN) schemes. IP multicasting over non-continuous transmission dynamic SFN achieves as much as 905% and 1054% gain respectively in system spectral efficiency and multiuser system  spectral efficiency, from broadcasting over MFN, and 425% and 442% gain respectively from  IP multicasting over MFN, for heterogeneous fading case. Additionally, the SFN schemes gives a diversity gain of 3 dB over MFN, that may be utilized to increase the coverage probability by 4.35% for the same data rate, or to increase the data rate by 27 % for the same coverage as MFN.   Keywords: IP multicasting, broadcasting, coverage probability, system spectral efficiency, multiuser system spectral efficiency, DVB-T/H, eMBMS, mobile TV, IP-TV, SFN, MFN, Dynamic SFN, PARPS, homogeneous, heterogeneous, zipf-law

There is a growing recognition that we cannot afford the provision of all new health care technologies, even those that are proven to be beneficial. This is increasingly true in the US, where health care spending is on an unsustainable upward trajectory. US health care spending is greatly in excess of that of other countries; however, with respect to key health metrics, the US health care system performs relatively poorly. Despite this, unlike many other developed countries economic evaluation, and more specifically cost effectiveness evidence, is used sparingly in the US health care system. Notably, the Centers for Medicare and Medicaid Services (CMS), administrators of the Medicare programme, state that cost-effectiveness evidence is not relevant to coverage decisions for medical technology and interventions evaluated as part of National Coverage Determinations (NCDs). The empirical aspect of this thesis evaluates the current use and potential value of using cost-effectiveness evidence in CMS NCDs. A database was built using data obtained from NCD decision memoranda, the medical literature, a Medicare claims database, and Medicare reimbursement information. The findings of the empirical work show that, CMS’s stated position notwithstanding, cost-effectiveness evidence has been cited or discussed in a number of coverage decisions, and there is a statistically significant difference between positive and non-coverage decisions with respect to cost effectiveness. When controlling for factors likely to have an effect on coverage decisions, the availability of cost-effectiveness evidence is a statistically significant predictor of coverage. In addition, the quality of the supporting clinical evidence, the availability of alternative interventions, and the recency of the decision are statistically significant variables. Further, when hypothetically reallocating resources in accordance with cost-effectiveness substantial gains in aggregate health are estimated. It is shown that using cost-effectiveness to guide resource allocation has an effect on resource allocation across patient populations and types of technology.

Investors accept that there is uncertainty, or risk, associated with equity investment returns. Consequently, equities are normally priced so that they provide a premium to the returns available on risk-free investments. Equity returns, however, are cyclical. There can be long periods when equity returns greatly exceed risk-free returns; there can be long periods when the premium disappears altogether. This thesis explores the influences and driving forces in equity markets, with a particular emphasis on the UK equity market. Both rational and irrational influences are examined and discussed. A General Literature Review examines the general progression in academic thinking in the area of equity pricing over four decades and takes a close look at the concepts of market efficiency and the challenges mounted by behavioural finance. The “equity risk premium puzzle” is also examined. Chapters 3 to 6 contain empirical studies of the variation in UK equity returns over time from four angles. The chapters look, respectively, at: macro-economic influences on the equity market; the relationship between equity returns and market volatility; the impact of variation in risk-free returns; a full decomposition of both ex-ante and ex-post equity returns. Reassuringly, the results confirm that the UK equity market is driven, in the main, by economic factors. However, the results also indicate that the full set of influences on the equity market is complex. The analyses undertaken suggest that significant swings occur in the risk premium element of expected equity returns. The results also suggest that there are periods when the UK equity market may be in disequilibrium with other financial markets. It is not the contention that many of the puzzles that have confronted equity market researchers over recent decades are now resolved by the analyses undertaken and presented in this thesis. It is to be hoped, however, that a useful platform has been built from which further investigation and analysis can be taken forward. In particular, it is suggested that comprehensive surveys of long-term expectations could lead to a better understanding of equity market mechanisms.

<p style="text-align: justify">U radu su prikazani rezultati ispitivanja energetske efikasnosti ravnih PSE. Cilj istraživanja je uvodenje i definisanje konstruktivnih, fizickih i radnih karakteristika ravnih,<br />niskotemperaturnih prijemnika sunceve energije sa aspekta povecanja energetske efikasnosti. Ispitana je mogucnost efikasnijeg prenosa toplote sa povr&scaron;ine apsorbera na radni medijum cime se smanjuju ukupni toplotni gubici.</p> / <p>In the paper are presented the result of energetic efficiency test of<br />flat plate solar collectors. The aim of test is introduction and<br />definition of constructive, physical and working characteristics of<br />flat plate low-temperature solar collectors from the incresing<br />energetic efficiency aspect. Possibility of higher efficiency of heat<br />transmision from the surface of absorber to the working fluid was<br />tested, with decresing of summary heat losses.</p>