IETF proposes the Differentiated Service(DiffServ) architecture for next-generation QoS networks. The main features of a DiffServ network are high scalability and compatibility. However, lacking of supporting QoS for individual flows becomes a problem. To remedy this problem, we propose an effective TCP transmission (ETCP) scheme based on the characteristics of TCP. The goal of this thesis is to make TCP transmission more effective. Because of the network complexity, we need to modify both the Ingress and Egress nodes. At Ingress node, we measure TCP congestion window(cwnd) and Round Trip Time(RTT), while at Egress node we monitor the throughput and embed a feedback ratio into TCP header of the acknowledge packets. When the throughput is below or over the target throughput, we adjust DSCP dynamically. The adjustment depends on both measured TCP congestion window and RTT. Each DSCP value is mapped with a delay time through Delayed-FIFO. Changing the delay time in Ingress node, we are able to control TCP transmission associated with RTT more effectively. For the purpose of the demonstration, we implement our scheme on Linux platform. We discuss the performance difference between the theoretical and practical results through experiments. Besides, from the implementation, we have shown that our proposed architecture is workable and compatible with today¡¦s network environment.

In 2005 the highest global surface temperature ever was recorded. A virtual consensus exists today among scientists that global warming is underway and that human greenhouse gas (GHG) emissions are a significant cause. Possible mitigation of climate change through reduction of net GHG emissions has become a worldwide concern. Under the United Nation’s Framework convention on Climate Change, the Kyoto Protocol was formed in 1997 and required ratifying countries to co-operate in stabilizing atmospheric GHG concentrations. The protocol took effect on February 16, 2005. The mitigation cost for reducing GHG emissions for the US economy has been argued to be high particularly through the energy sector. Agriculture and Forestry (AF) can provide some low cost strategies to help with this mitigation principally through carbon sequestration but must be competitive with mitigation costs in the rest of the economy. A general equilibrium approach is used herein to evaluate the role of AF mitigation in an economy wide setting. The results show that the AF sectors have significant mitigation potential. Higher carbon prices lead to more sequestration, less emissions, reduced consumer and total welfare, improved environmental indicators and increased producer welfare. AF mitigation increases as the carbon price increase over time. In the earlier periods, while the carbon price is low, AF emissions and sink are quite small compared to the energy sector. As carbon prices increase over time, the AF sectors mitigate about 25% of the net emissions. This verifies McCarl et al's (2001) argument that the AF sectors “may be very important in a world that requires time and technological investment to develop low-cost greenhouse gas emission offsets.” AF GHG emission mitigation is sensitive to saturation of sequestration sinks. This research finds that ignoring saturation characteristics leads to a severe overestimate of mitigation potential with estimates being inflated by as much as a factor of 6.

In 2005 the highest global surface temperature ever was recorded. A virtual consensus exists today among scientists that global warming is underway and that human greenhouse gas (GHG) emissions are a significant cause. Possible mitigation of climate change through reduction of net GHG emissions has become a worldwide concern. Under the United Nation’s Framework convention on Climate Change, the Kyoto Protocol was formed in 1997 and required ratifying countries to co-operate in stabilizing atmospheric GHG concentrations. The protocol took effect on February 16, 2005. The mitigation cost for reducing GHG emissions for the US economy has been argued to be high particularly through the energy sector. Agriculture and Forestry (AF) can provide some low cost strategies to help with this mitigation principally through carbon sequestration but must be competitive with mitigation costs in the rest of the economy. A general equilibrium approach is used herein to evaluate the role of AF mitigation in an economy wide setting. The results show that the AF sectors have significant mitigation potential. Higher carbon prices lead to more sequestration, less emissions, reduced consumer and total welfare, improved environmental indicators and increased producer welfare. AF mitigation increases as the carbon price increase over time. In the earlier periods, while the carbon price is low, AF emissions and sink are quite small compared to the energy sector. As carbon prices increase over time, the AF sectors mitigate about 25% of the net emissions. This verifies McCarl et al's (2001) argument that the AF sectors “may be very important in a world that requires time and technological investment to develop low-cost greenhouse gas emission offsets.” AF GHG emission mitigation is sensitive to saturation of sequestration sinks. This research finds that ignoring saturation characteristics leads to a severe overestimate of mitigation potential with estimates being inflated by as much as a factor of 6.

This doctoral thesis consists of five self-contained essays.Common themes that unify the essays are the conditions for innovative engagements and the effort to endogenize innovations into the explanation of profitability, productivity and growthin manufacturing and service production. The purpose is to explore the importance of innovation in explaining heterogeneity in the performance of firms. The traditional analysis of the relationship between research and developmentand productivity is extended and developed by using, on the onehand, firm-level data not previously available and, on theother, a modern state-of-the-art econometric framework. Essay I. Methods and results are reviewed and stylized facts presented regarding the return on innovation. The limitations of the data and methods used in mainstream literature are discussed. A set of firm-level observations recently made available and a multiple knowledge production function analysis have been used to clarify the role of innovation in explaining performance heterogeneity among manufacturing firms inSweden. Essay II. The relationships between innovation and productivity among manufacturing firms in Finland, Norway and Sweden are studied. The main purpose is to investigate the contributions of firm-level innovation in creating the large observed differences in aggregated productivity growth between Norway on the one hand and Finland and Sweden on the other. Essay III. The focus of this essay is threefold. One, since innovation has been found to be a major contributor to productivity growth in manufacturing, we seek to find whether there is any evidence for the notion that service industrie shave a lower propensity to be innovative or that they are less efficient in deriving benefits from innovations. Second, we consider what real productivity growth does, and what the measurement methods do to produce the reported weak growthrates in services. Third, given that intermediate services have been found to be one of the fastest growing input factors inmanufacturing, largely reflecting the replacement of internally provided activities by externally produced outputs, we examine what the impact of outsourcing is on productivity growth in manufacturing. The essay brings a comparative perspective to these issues by analyzing the firm-level data on innovativeactivities and economic performance in knowledge-intensive manufacturing and service firms in Sweden. Essay IV.This essay investigates the sensitivity of estimated relationships between innovation and firm performance. The essay compares the sensitivity of results with regards to different types of models, estimation methods, measures of firm performance, classification of firms, type of innovations and data sources. The analyses are performed on both the level and growth rate of firm performance, and theinfluence of outliers is explored. Essay V. The role of capital structure and external financing in innovation and production is studied. Results from different model specifications are explored. A preferred dynamic model with flexible adjustment is used for an inter-country and an intra-country comparison of the determinants of the optimal mix between debt and equity as wellas the rate of change towards an optimal capital structure. / <p>QC 20100526</p>

Corporate Financial Planning--A System Dynamic Approach.

Από τα μέσα της δεκαετίας του 1990 οι φορητές συσκευές έχουν συμβάλλει θεαματικά στη διευκόλυνση της καθημερινής ζωής των ανθρώπων και των επιχειρήσεων. Ειδικά τα τελευταία χρόνια με την τεράστια ανάπτυξη των έξυπνων τηλεφώνων (smartphones), των λειτουργικών στα οποία βασίζονται, την εύκολη και γρήγορη πρόσβαση στο διαδίκτυο οι συσκευές αυτές έχουν γίνει περισσότερο αυτόνομες. Σήμερα τα περισσότερα smartphones είναι μόνιμα συνδεδεμένα με το διαδίκτυο και οι συσκευές αυτές μπορούν να υποστηρίξουν standard HTTP και HTML. Όμως για τις περισσότερες υπηρεσίες του διαδικτύου υπάρχει και μία αντίστοιχη εφαρμογή που οι χρήστες πρέπει να κατεβάσουν, να εγκαταστήσουν και να τρέξουν. Έτσι, η χρήση των περιηγητών διαδικτύου από τις φορητές συσκευές περιορίζεται σημαντικά. Λόγω αυτού του γεγονότος οι χρήστες είναι αναγκασμένοι να έχουν εγκατεστημένο ένα μεγάλο πλήθος εφαρμογών προκειμένου να εξυπηρετήσουν τις ανάγκες τους. Οι περισσότερες εφαρμογές απαιτούν συχνά ενημερώσεις και η κατάληξη αυτής της διαδικασίας είναι ο χρήστης να χάνει τον έλεγχο της διαχείρισης των εφαρμογών και να προκύπτουν διάφορα προβλήματα. Ένα από αυτά είναι ότι οι πληροφορίες του χρήστη γίνονται πιο ευάλωτες εξαιτίας των δικαιωμάτων πρόσβασης των εφαρμογών οι οποίες μπορεί να αλλάξουν με την ενημέρωση της εφαρμογής χωρίς ο χρήστης να το αντιληφθεί. Επίσης, είναι σύνηθες πολλές εφαρμογές να διαφέρουν ελάχιστα μεταξύ τους με αποτέλεσμα ο χρήστης να καταλήγει με περισσότερες εφαρμογές από ότι πραγματικά χρειάζεται, οι οποίες θα μπορούσαν να αντικατασταθούν από μία. Στο πλαίσιο της παρούσας μεταπτυχιακής εργασίας, προτείνεται και υλοποιείται ένα σύστημα που σα σκοπό έχει να επιλύσει τα παραπάνω προβλήματα. Το σύστημα αποτελείται από μία web διεπαφή (web interface), κάποιες υπηρεσίες διαδικτύου (web services) και μία client εφαρμογή για φορητές συσκευές σε περιβάλλον Android. Ο διαχειριστής του συστήματος σχεδιάζει μέσω της web διεπαφής τη διάταξη και τη λειτουργικότητα της εφαρμογής, η οποία γίνεται διαθέσιμη στην client εφαρμογή μέσω μίας υπηρεσίας διαδικτύου που παράγει ένα αρχείο ρυθμίσεων. Η client εφαρμογή αναλαμβάνει τη «μετάφραση» του αρχείου και την παρουσίαση της τελικής εφαρμογής στον χρήστη. / Since the middle of 1990s mobile devices assist people in their daily life and business. The last few years the market of the smartphones has grown rapidly. The operating systems that they are built on and the fast and easy access on the Internet made these devices become more and more standalone. Today’s smartphones are permanently connected to the Internet and can support standard HTML and HTTP. Nevertheless, dedicated Internet applications are offered to replace generic www-browsers. For most services in the Internet users are requested to download, install and run special applications. From user’s perspective, in order to service their needs they are forced to have installed too many applications which need to be updated regularly because new functionality is added. Because of this situation users lose control of this administrative process and problems arise quite often. One of them is that user’s personal information become vulnerable as the access rights of applications might change with each update without the user getting noticed for it. Moreover, it is common that many applications have very slight differences between them and as a result the user may end up having two or more applications installed assigned to perform the same task. These applications could eventually be replaced by one. Within this postgraduate project a proposed system is built in order to address the issues mentioned above. The system consists of a web interface, some web services and a client application for Android mobile devices. Through the web interface, the administrator of the system constructs the layout and the functionality of an application. This application is then available to the mobile device through a web service that generates a configuration file. The client application parses the configuration file, constructs the application dynamically and presents it to the user.

本論文將Poterba(1984)所建構的房屋市場模型由部分均衡擴展為一般均衡，引入貸款成數及加碼利率做宣示效果分析。探討民眾在未預料到和預料到的兩種情況下，貸款成數及加碼利率變動對房價和房屋存量的影響，可得到結論如下： 一、當貸款成數降低時，不論房量變動的正負效果相對大小如何，均會使長期的房屋價格下跌和房屋存量減少。 二、當加碼利率提高時，在加碼利率變動的正效果大於負效果的情況下，長期的房屋存量和房屋價格均上升；反之，當加碼利率變動的正效果小於負效果，長期的房屋存量和房屋價格均會減少。 三、政府可利用降低貸款成數達到抑制房價的政策目標；但若要以提高加碼利率達成抑制房價的目標，則要視加碼利率的正負效果相對大小而定。 四、政策宣告會改變民眾的預期，促使房價於政策宣告後立即跳動，並在政策執行前就已對房屋存量和房價做出反應。在宣告降低貸款成數的瞬間，房價會有跳躍性減少的情況；但在宣告提高加碼利率的瞬間，房價則視加碼利率變動的正負效果相對大小，有跳躍性上升或下降的情況。 / This thesis extends the housing market model pioneered by Poterba(1984) from a partial equilibrium analysis to a general equilibrium analysis. The purpose of this thesis is to analyze how the anticipated and unanticipated policies of the loan-to-value ratio and the mark-up rate govern the transitional dynamics of housing prices and the housing stock. There are two main findings emerge from the analysis. First, a reduction in the loan-to-value ratio leads to a decline in both of housing prices and the housing stock, regardless of whether the increased loan-to value ratio is beneficial or harmful to the return on housing. Second, in response to a rise in the mark-up rate, whether the steady-state housing prices and the housing stock go up or go down depends on the mark-up rate effect. Both housing prices and the housing stock go up if the increased mark-up rate contributes a positive effect on the return of holding houses. By contrast, the steady-state housing prices and the housing stock go down if the increased mark-up rate causes a negative effect on the return on housing holdings.

無 / This study investigates the monetary effects under the floating exchange rates and imperfect capital mobility by extending the model of Bernanke and Blinder (1988) into a small open economy. It is shown that with credit channel of monetary transmission explicitly considered, the effect of monetary policy on output may be augmented or lessen in our model depending on whether the exchange rate depreciates or appreciates. In addition, the exchange rate puzzle found in the empirical studies can be explained in our theoretical model. The dynamic adjustment patterns of the output and the exchange rate after an increase in money supply are further examined. Under the case of relative high capital mobility, when the real output gradually adjusts toward a higher level, the exchange rate may overshoot, undershoot, or even counter-shoot during the dynamic adjustment process. This provides another one explanation for the volatility of exchange rates under floating rates. Therefore, as financial markets become more internationalized, the conduct of monetary policy turns more complicated in an open economy.

本篇論文試圖藉由比較一個產業生產技術為固定規模報酬的經濟體系，如何因外部因素的影響而改變其動態調整方式。在此考慮的外部因素有資本移動的開放與否、生產要素的外部性、及政府對要素報酬的課稅。考慮各種因素後，所得出的結論為在生產函數為Cobb-Douglas型式且產業生產技術為固定規模報酬的情況下： 1.多重均衡路徑在資本帳封閉時期唯有效用函數為特例時才能使其出現，但在資本自由移動時期對於所有的效用函數型態皆會成立。 2.其他條件保持不變之下，單獨存在生產要素外部性或是對要素所得課稅皆可使體系存在多重均衡路徑。 3.其他條件保持不變之下，若生產要素外部性與要素所得稅皆同時存在時，可使體系存在唯一的穩定馬鞍路徑。