The lifetime of a Giant Molecular Cloud (GMC) and the total mass of stars that form within it are crucial to the understanding of star formation rates across a whole galaxy. In particular, the stars within a GMC may dictate its disruption and the quenching of further star formation. Indeed, observations show that the Milky Way contains GMCs with extensive expanding bubbles while the most massive stars are still alive. Simulating entire GMCs is challenging, due to the large variety of physics that needs to be included, and the computational power required to accurately simulate a GMC over tens of millions of years. Using the radiative-magneto-hydrodynamic code Enzo, I have run many simulations of GMCs. I obtain robust results for the fraction of gas converted into stars and the lifetimes of the GMCs: (A) In simulations with no stellar outputs (or ``feedback''), clusters form at a rate of 30% of GMC mass per free fall time; the GMCs were not disrupted but contained forming stars. (B) Including ionization gas pressure or radiation pressure into the simulations, both separately and together, the star formation was quenched at between 5% and 21% of the original GMC mass. The clouds were fully disrupted within two dynamical times after the first cluster formed. The radiation pressure contributed the most to the disruption of the GMC and fully quenched star formation even without ionization. (C) Simulations that included supernovae showed that they are not dynamically important to GMC disruption and have only minor effects on subsequent star formation. (D) The inclusion of a few micro Gauss magnetic field across the cloud slightly reduced the star formation rate but accelerated GMC disruption by reducing bubble shell disruption and leaking. These simulations show that new born stars quench further star formation and completely disrupt the parent GMC. The low star formation rate and the short lifetimes of GMCs shown here can explain the low star formation rate across the whole galaxy.

The lifetime of a Giant Molecular Cloud (GMC) and the total mass of stars that form within it are crucial to the understanding of star formation rates across a whole galaxy. In particular, the stars within a GMC may dictate its disruption and the quenching of further star formation. Indeed, observations show that the Milky Way contains GMCs with extensive expanding bubbles while the most massive stars are still alive. Simulating entire GMCs is challenging, due to the large variety of physics that needs to be included, and the computational power required to accurately simulate a GMC over tens of millions of years. Using the radiative-magneto-hydrodynamic code Enzo, I have run many simulations of GMCs. I obtain robust results for the fraction of gas converted into stars and the lifetimes of the GMCs: (A) In simulations with no stellar outputs (or ``feedback''), clusters form at a rate of 30% of GMC mass per free fall time; the GMCs were not disrupted but contained forming stars. (B) Including ionization gas pressure or radiation pressure into the simulations, both separately and together, the star formation was quenched at between 5% and 21% of the original GMC mass. The clouds were fully disrupted within two dynamical times after the first cluster formed. The radiation pressure contributed the most to the disruption of the GMC and fully quenched star formation even without ionization. (C) Simulations that included supernovae showed that they are not dynamically important to GMC disruption and have only minor effects on subsequent star formation. (D) The inclusion of a few micro Gauss magnetic field across the cloud slightly reduced the star formation rate but accelerated GMC disruption by reducing bubble shell disruption and leaking. These simulations show that new born stars quench further star formation and completely disrupt the parent GMC. The low star formation rate and the short lifetimes of GMCs shown here can explain the low star formation rate across the whole galaxy.

Abstract Small medium enterprise had been the primary contributors to the Economical Miracle in Taiwan in the past decades. Although they had their merits in macro-economy, they could hardly escape the fate of pioneers. Not only had they experienced the hardship and sacrifice but also the probability of transforming into large-size corporations was close to zero. Witnessing the struggle of these businesses, this study is expected to provide some solid suggestions. With which, small medium enterprises could survive the change of the era and the impact of globalization. Hopefully, this study will help in their continuous growth and development. According to the references, we find ¡§lack of resources¡¨ is fatal to those businesses. ¡§Changes in the markets all around¡¨ puts more risk in their operations. Therefore, this study is designed to use the before-mentioned key factors as its major pillars. The analysis has shown that the so-called ¡§lack of resources¡¨ was basically ¡§the absence of strategy-oriented mind¡¨ which was caused by lacking knowledge. The ¡§Strategy Factors¡¨, the focuses of this study, such as Scope of Operation, Managerial Capabilities, Utilization of Resources, Strategic Alliance, and Organizational Abilities, etc. are all based on ¡§Resource Theory¡¨. The research framework of this study is primarily designed as that suggested in ¡§the stable growth cycle of small medium enterprise¡¨,(by Dr. Fong¡K) combined with ¡§the organizing ability of corporations¡¨ and ¡§major strategies of each phase¡¨. As to ¡§sense-making¡¨ learning, this research aims at ¡§the how-to in Entrepreneurship¡¨ and hopes to involve extensive discussions and findings supported by real cases rather than by functionalities. Consequently, this research is expected to offer strategic suggestions with reference value to the businesses in various development phases.

Gay life ; Three baritone songs / David Del Tredici. / text

Wireless Mesh Networks (WMNs) are dynamically self-organized and self-configured, where the nodes in the network automatically establish an ad hoc network and maintain mesh connectivity. These properties make WMNs a key technology for next generation wireless networking. However, supporting Quality of Service (QoS) to enable multimedia services is still one of the major issues in next-generation WMNs. In distributed systems like WMNs, the Medium Access Control (MAC) layer is considered very important in the IEEE 802.11-based wireless networks, as it supports many crucial operational functions. Hence, QoS support in WMNs can be enhanced through the efficient cross-layer design of MAC protocols that utilizes advanced physical layer technologies viz Multiple-Input Multiple-Output (MIMO) with its multiple spatial channels that are capable of simultaneous receive or transmit streams. MIMO has become a very attractive technology in providing support for different QoS requirements. In this thesis we propose a novel QoS MIMO-aware MAC Protocol (QMMP). QMMP is a MAC protocol framework that exploits the MIMO system gains to boost QoS support. The proposed MAC framework includes the following components. The first component enables concurrent sharing of the increased MIMO bandwidth, i.e., instead of allocating all the spatial channels to one connection, connections can concurrently share the increase bandwidth via splitting the spatial channels. The second component reduces the medium access collisions problem. In distributed systems like WMNs, medium access collisions have a noticeably negative impact on resource (bandwidth) utilization as they leave the bandwidth unutilized for a long time. To address this problem, we propose a spatial channels sharing scheme during medium contention period. The third component boosts the bandwidth utilization during data transmission. We propose resource management schemes that adapt the physical data rate and the aggregation frame length according to the instantaneous channel quality. Then we propose a QoS-aware bandwidth provisioning mechanism that performs effective bandwidth distribution to further boost QoS support. / Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2009-01-26 10:11:16.729

In Jordan around 98 percent of manufacturing and service sector firms are small and medium-sized enterprises (SMEs), while around 80 percent of the Jordanian labour force is employed by S MEs. However, SMEs face considerable difficulties in obtaining sufficient funds, especially from external sources such as commercial banks. This has been recognized in Jordan by the establishment of a loan guarantee scheme in 1994. However, neither this nor any other similar scheme introduced by a developing country has b een fully evaluated to establish its impact and success. The purpose is to evaluate the effects of the Jordanian loan guarantee scheme to establish its role in improving the supply of funds to SMEs, and to suggest policies and procedures for the improvement of the scheme. The methodology for the study is based upon an interview questionnaire survey of 142 Jordanian firms receiving loans from the commercial banks backed by a guarantee. It covers firms in different types of business (manufacture, services, retail and agriculture) and in different locations (Amman, Zarqa, Irbid, Balqa and Aqaba). The study also utilizes interviews with the credit managers of commercial banks participating in the loan guarantee scheme. The thesis is organized around nine chapters including on the Jordanian economy, SMEs in Jordan, a literature review of loan guarantee schemes and the qualitative and quantitative results of the surveys. The main findings are that younger borrowers and newer SME firrns are more able to receive commercial bank ftinding under the scheme than they would otherwise obtain. The scheme also helps firms with uncertain profitability and projects that are traditionally viewed as 'low quality' (e. g. low level of education or female entrepreneurs) to obtain extra finance. These projects have low default rates and do not have high failure rates suggesting a substantial market failure. However, the study finds that the commercial banks tend to use the scheme as an additional source of security in their lending, and do not necessarily lend to riskier projects, as they require similar levels of collateral. Further, the study draws attention to the management of the scheme, so that it needs to be better marketed to the target group and there needs to be better monitoring and follow-up of projects. Lessons could also be leamt from other guarantee schemes, such as in the UK, including the introduction of a premium charge for firms.

Proefschrift Universiteit van Amsterdam. / Met lit. opg. - Met samenvatting in het Nederlands.

Thesis (PhD) - Institute for Social Research, Swinburne University of Technology, 2006. / Thesis submitted in fulfillment of the requirements of the degree of Doctor of Philosophy, Institute for Social Research, Swinburne University of Technology, 2006. Typescript. 'December 2006'. Includes bibliographical references (p. 303-326).

Thesis (D. Mus. Arts)--University of Washington, 1999. / For baritone and orchestra; originally for tenor and piano. Vita. Includes bibliographical references (leaf 91).

Thesis (Aeronautical Engineer). / Includes bibliographical references.