Uganda faces considerable challenges in revamping economic growth performance, reducing the proportional of people living below the poverty line to below 20 percent, and attaining other Millennium Development Goals by the year 2015. These developments have prompted the government to prioritise poverty alleviation and the attainment of sustainable real GDP growth (i.e. at 7 percent per annum), among other policies. This dissertation argues that a proper identification of the critical sectors of growth with significant linkages to the rest of the economy can guide policy makers to affect the outcomes of external shocks (e.g. by redirecting resources to sectors with potential for higher output growth and welfare effects) .Using the 2002 Social Accounting Matrix (SAM) for Uganda, we investigate the properties of the multipliers that can be calculated from the SAM, in particular contrasting them with the simpler input-output multipliers. Using the SAM multipliers, the computed linkages suggest that Agriculture, Food Processing, and Other Services (Trade, and Health and Education) are the key sectors of Uganda’s economy. Similarly, Manufacturing, Construction, and Transport were found to be sectors with weak linkages to the rest of the economy. Moreover, the multiplier impact on output, employment, and household income distribution is higher with in agriculture relative to other sectors. Our multiplier results confirm the need for policy makers in Uganda to target agriculture-led growth if Uganda is to substantially raise economy wide growth, and to improve household incomes for significant poverty alleviation. Policies to boost the agriculture sector include: building and maintaining feeder roads, provision of farm inputs, training farmers on better methods of production and productivity, reviving cooperatives (i.e. to enable coordinated farming activities, storage, processing, and marketing of farmers produce, and easy access to credit from lending institutions). It should be noted that Agriculture in Uganda is characterised by low productivity resulting from the use of poor inputs, undeveloped value chains, and low public and private investment in the sector. Government should significantly invest in agro-processing industries to increase value addition and exports for higher incomes. Since such investments are costly, requiring significant capital investments which majority of poor farmers cannot afford, the government should promote public-private sector partnership. It should be noted that Uganda’s exports are dominated by unprocessed primary low products which fetch low earnings from world markets. Using a country specific CGE model and selected exogenous changes and policies, our findings suggest that an increase in the world price of exports and workers remittances, and a decrease in import tariffs are growth and welfare enhancing with the positive shock to world export prices producing the largest impact on real GDP, employment (largely, low skilled labour and in agriculture), factor and household incomes. The significant role of migrant remittances in growth and poverty alleviation (i.e. by increasing household incomes, and investment in agriculture, education, and real estate among others) is worth noting. These findings suggest that Ugandan authorities could encourage Ugandans living and working abroad to invest at home by introducing a diaspora bond and sharing information on investment opportunities to encourage increased inflow of workers remittances which would boost domestic investment. Where possible, surplus labour could be exported to other regions or countries and arrangements made to have workers remittances invested in Uganda. In all the policy experiments performed, we find that the welfare of households in the northern and eastern regions of the country is lower compared to that of households based in other regions. This suggests that the government needs to design and implement specific poverty alleviation programs in these regions. The relatively high poverty in northern and eastern regions is attributed to the 19 year civil conflict and the communal land ownership which limits agriculture production for food security and improved household incomes. The government could increase the provision of social and physical infrastructure and promote sustainable agriculture by opening up irrigation schemes, supplying farmers with drought resistant crops, restocking farms, and building and maintain valley dams, and implementing land reforms which promote agriculture. Given the importance of agriculture to Uganda’s growth and poverty alleviation prospects, we argue that the government should implement the recommendations of the Comprehensive African Agriculture Development Program (CAADP) and the Maputo Declaration which calls for the allocation of 10 percent of the national budget to agriculture. This allocation is necessary to achieve the target of agriculture sector growth by 6 percent which is required to reduce significantly the number of Ugandans living in extreme poverty and hunger. The budgetary allocation of 4 percent coupled with inadequate supervision, and corruption and misallocation of funds meant for agriculture development programs have contributed to persistent decline in in output and increase in rural and urban poverty. Our results suggest agriculture is associated with higher employment of low skilled labour which is the largest labour force in Uganda. According to the World Bank, employment is the surest way to poverty alleviation. Thus, Uganda should pursue an agriculture led growth strategy for poverty alleviation and sustained economic growth. However, to substantially increase household incomes and contribute to poverty alleviation, policy interventions in agriculture should focus on increasing value addition through food processing and exports. Further, interventions that empower women to own assets should be enforced by government. Women are the principal users of land, and they must have stronger rights over the resources they depend upon. Our simulations have demonstrated that employment and incomes of women increase from interventions that target the agriculture sector in Uganda. Women constitute over 90 percent of the total labour force employed in agriculture and earn less or none of farm incomes, and most of them operate under chronic poverty. To gain greater knowledge of and control over their environment and build more productive sustainable systems, the government could empower women with basic education and training, increase their access to new technologies and mobilise them to participate in rural saving banks and cooperatives to boost their earnings from agriculture. Our results suggest that Services (mainly education and health) are potential candidates for growth and poverty alleviation in Uganda because they generate significant employment. However, Uganda, Services employ high skilled labour and are urban based, implying they cannot absorb the dominant low skilled labour and the youth. According to the Uganda Bureau of Statistics, Uganda currently has about 34.5 million people of which about 65 percent are youth. About 83 percent of these youth (aged 18-30 years) have no formal employment. This calls for authorities in Uganda to reorient the current curriculum towards her development needs where the youth and graduates are trained to be job creators and not job seekers. Massive investment in vocation training where the youth are trained and equipped with skills to manage their own lives by engaging in small scale projects should be prioritised by the government. To overcome the high rate of youth and graduate unemployment in developing countries Uganda inclusive, the donor community in collaboration with African governments identified vocational training as a critical component in each country’s poverty reduction strategy.

Full scale lateral load testing was performed on four 12.75x0.375 pipe piles spaced at 3.9, 2.9, 2.8, and 1.7 pile diameters behind an MSE wall which was constructed for this research to determine appropriate reduction factors for lateral pile resistance based on pile spacing behind the back face of the wall. The load induced on eight soil reinforcements located at various transverse distances from the pile and at different depths was monitored to determine the relationship between lateral load on the pile and load induced in the reinforcement. Each pile was loaded towards the wall in 0.25 in. increments to a total deflection of 3.0 in. Additionally, wall panel displacement was also monitored to determine if it remained in acceptable bounds. The results of the research indicate that pile resistance tends to decrease as spacing decreases. P-multipliers for the 3.9, 2.9, 2.8, 1.7D tests were found to be 1.0, 1.0, 1.0, and 0.5, respectively using back-analysis with the computer model LPILE. However, these multipliers are higher than expected based on previous testing and research. Piles spaced further than 3.8D can be assumed to have no interaction with the wall. The resistance of piles spaced closer to the wall than 3.8D can be modeled in LPILE using a p-multiplier less than 1.0. The reinforced backfill can be modeled in LPILE using the API Sand (1982) method with a friction angle of 31º and a modulus of approximately 60 pci when a surcharge of 600 psf is applied. If no surcharge is applied, a friction angle of 39º and modulus of 260 pci is more appropriate. Maximum wall panel displacement was highest for the 2.8D test and was 0.35 in. at 3.0 in. of pile head displacement. For all the other tests, the maximum wall displacement at 3.0 in. of pile head displacement was similar and was approximately 0.15 inches. Induced load in the soil reinforcement increases with depth to the 2nd or 3rd layer of reinforcement after which it decreases. Induced load in the reinforcement increases as pile spacing decreases. Induced load in the reinforcement decreases rapidly with increased transverse distance from the pile. Induced load in the reinforcement can be estimated using a regression equation which considers the influence of pile load, pile spacing behind the wall, reinforcement depth or vertical stress, and transverse spacing of the reinforcement.

Pile foundations for bridges must often resist lateral loads produced by earthquakes and thermal expansion and contraction of the superstructure. Right-of-way constraints near bridge abutments are leading to an increased use of mechanically stabilized earth (MSE) walls below the abutment. Previous research has shown that lateral pile resistance can be greatly reduced when piles are placed close to MSE walls but design codes do not address this issue. A full-scale MSE wall was constructed and 24 lateral load tests were conducted on pipe, square and H piles spaced at distances of about 2 to 5 pile diameters from the back face of the wall. The MSE wall was constructed using welded-wire grid and ribbed strip inextensible reinforcements. This paper focuses on four lateral load tests conducted on steel pipe piles located behind a 20-ft section of MSE wall reinforced with welded-wire grids. Results showed that measured lateral resistance decreases significantly when pipe piles are located closer than about 4 pile diameters from the wall. LPILE software was used to back-calculate P-multipliers that account for the reduced lateral resistance of the pile as a function of normalized spacing from the wall. P-multipliers for this study were 0.95, 0.68, and 0.3 for piles spaced 4.3, 3.4 and 1.8 pile diameters from the wall, respectively. Based on results from this study and previous data, lateral pile resistance is relatively unaffected (p-multiplier = 1.0) for piles spaced more than approximately 3.9 pile diameters (3.9D) from the MSE wall. For piles spaced closer than 3.9D, the p-multiplier decreased linearly as distance to the wall decreased. P-multipliers were not affected by differences in reinforcement length to height (L/H) ratio or reinforcing type. Lateral pile loads induce tensile forces in the soil reinforcement such that, as pile load increases the maximum induced tensile force increases. Results also indicate that maximum tensile forces typically occurred in the soil reinforcement near the pile location. Past research results were combined with data from this study and a statistical regression analysis was performed using all data associated with welded-wire grid reinforcements. A regression equations was developed to predict the peak induced tensile force in welded-wire grids based on independent variables including lateral pile load, normalized pile distance (S/D), transverse distance (T/D), L/H ratio, and vertical stress. The equation has an R2 value of 0.79, meaning it accounts for approximately 79% of variation for all welded-wire grid reinforcements tested to date.

<p>Currently film is being replaced by electronic detectors for portal imaging in radiation therapy. This development offers obvious advantages such as on-line quality assurance and digital images that can easily be accessed, processed and communicated. In spite of the improvements, the image quality has not been significantly enhanced, partly since the quantum efficiency compared to film is essentially the same, and the new electronic devices also suffer from sensitivity to the harsh radiation environment. In this thesis we propose a third generation electronic portal imaging device with increased quantum efficiency and potentially higher image quality.</p><p>Due to the parallel readout capability it is much faster than current devices, providing at least 200 frames per second (fps), and would even allow for a quality assurance and adaptive actions after each accelerator pulse. The new detector is also sensitive over a broader range of energies (10 keV - 50 MeV) and can be used to obtain diagnostic images immediately prior to the treatment without repositioning the patient. The imaging could be in the form of portal imaging or computed tomography. The new detector is based on a sandwich design containing several layers of Gas Electron Multipliers (GEMs) in combination with, or integrated with, perforated converter plates. The charge created by the ionizing radiation is drifted to the bottom of the assembly where a tailored readout system collects and digitizes the charge. The new readout system is further designed in such a way that no sensitive electronics is placed in the radiation beam and the detector is expected to be radiation resistant since it consists mainly of kapton, copper and gas.</p><p>A single GEM detector was responding linearly when tested with a 50 MV photon beam at a fluence rate of ~10¹⁰ photons mm^-2 s^-1 during 3-5 μs long pulses, but also with x-ray energies of 10-50 keV at a fluence rate of up to ~10⁸ photons mm^-2 s^-1. The electron transmission of a 100 μm thick Cu plate with an optical transparency of ~46% was found to be ~15.4%, i.e. the effective hole transmission for the electrons was about one third of the hole area. A low effective GEM gain is enough to compensate for the losses in converters of this dimension. A prototype for the dedicated electronic readout system was designed with 50 x 100 pixels at a pitch of 1.27 mm x 1.27 mm. X-ray images were achieved with a single GEM layer and also in a double GEM setup with a converter plate interleaved. To verify the readout speed a Newton pendulum was imaged at a frame rate of 70 fps and alpha particles were imaged in 188 fps. The experimental studies indicates that the existing prototype can be developed as a competitive alternative for imaging in radiation therapy.</p>

<p>Automotive Radars have introduced various functions on automobiles for driver’s safety and comfort, as part of the Intelligent Transportation System (ITS) including Adaptive Cruise Control (ACC), collision warning or avoidance, blind spot surveillance and parking assistance. Although such radar systems with 24 GHz carrier frequency are already in use but due to some regulatory issues, recently a permanent band has been allocated at 77-81 GHz, allowing for long-term development of the radar service. In fact, switchover to the new band is mandatory by 2014.</p><p>A frequency multiplier will be one of the key components for such a millimeter wave automotive radar system because there are limitations in direct implementation of low phase noise oscillators at high frequencies. A practical way to build a cost-effective and stable source at higher frequency is to use an active multiplier preceded by a high spectral purity VCO operating at a lower frequency. Recent improvements in the performance of SiGe technology allow the silicon microelectronics to advance into areas previously restricted to compound semiconductor devices and make it a strong competitor for automotive radar applications at 79 GHz.</p><p>This thesis presents the design of active frequency doubler circuits at 20 GHz in a commercially available SiGe BiCMOS technology and at 40GHz in SiGe bipolar technology (Infineon-B7h200 design). Buffer/amplifier circuits are included at output stages to drive 50 Ω load. The frequency doubler at 20 GHz is based on an emitter-coupled pair operating in class-B configuration at 1.8 V supply voltage. Pre-layout simulations show its conversion gain of 10 dB at -5 dBm input, fundamental suppression of 25dB and NF of 12dB. Input and output impedance matching networks are designed to match 50 Ω at both sides.</p><p>The millimeter wave frequency doubler is designed for 5 V supply voltage and has the Gilbert cell-based differential architecture where both RF and LO ports are tied together to act as a frequency doubler. Both pre-layout and post-layout simulation results are presented and compared together. The extracted circuit has a conversion gain of 8 dB at -8 dB input, fundamental suppression of 20 dB, NF of 12 dB and it consumes 42 mA current from supply. The layout occupies an area of 0.12 mm2 without pads and baluns at both input and output ports. The frequency multiplier circuits have been designed using Cadence Design Tool.</p>

<p>The work describes the development of a reliable device for profiling anion beam in the intensity cross section. A sensor head consisting of a Faradaycup in combination with a Channel Electron Multiplier was designedand built together with electronics including power supply and front endelectronics. The design was chosen considering financial and long term lifeaspects. Testing, first calibration and error analysis were done using the ionbeam facilities where the unit is supposed to be installed permanently. Theprofiling system performed as designed and the profile of the ion beam couldbe measured reliably with an accuracy down to the femto ampere range.</p>

Currently film is being replaced by electronic detectors for portal imaging in radiation therapy. This development offers obvious advantages such as on-line quality assurance and digital images that can easily be accessed, processed and communicated. In spite of the improvements, the image quality has not been significantly enhanced, partly since the quantum efficiency compared to film is essentially the same, and the new electronic devices also suffer from sensitivity to the harsh radiation environment. In this thesis we propose a third generation electronic portal imaging device with increased quantum efficiency and potentially higher image quality. Due to the parallel readout capability it is much faster than current devices, providing at least 200 frames per second (fps), and would even allow for a quality assurance and adaptive actions after each accelerator pulse. The new detector is also sensitive over a broader range of energies (10 keV - 50 MeV) and can be used to obtain diagnostic images immediately prior to the treatment without repositioning the patient. The imaging could be in the form of portal imaging or computed tomography. The new detector is based on a sandwich design containing several layers of Gas Electron Multipliers (GEMs) in combination with, or integrated with, perforated converter plates. The charge created by the ionizing radiation is drifted to the bottom of the assembly where a tailored readout system collects and digitizes the charge. The new readout system is further designed in such a way that no sensitive electronics is placed in the radiation beam and the detector is expected to be radiation resistant since it consists mainly of kapton, copper and gas. A single GEM detector was responding linearly when tested with a 50 MV photon beam at a fluence rate of ~1010 photons mm-2 s-1 during 3-5 μs long pulses, but also with x-ray energies of 10-50 keV at a fluence rate of up to ~108 photons mm-2 s-1. The electron transmission of a 100 μm thick Cu plate with an optical transparency of ~46% was found to be ~15.4%, i.e. the effective hole transmission for the electrons was about one third of the hole area. A low effective GEM gain is enough to compensate for the losses in converters of this dimension. A prototype for the dedicated electronic readout system was designed with 50 x 100 pixels at a pitch of 1.27 mm x 1.27 mm. X-ray images were achieved with a single GEM layer and also in a double GEM setup with a converter plate interleaved. To verify the readout speed a Newton pendulum was imaged at a frame rate of 70 fps and alpha particles were imaged in 188 fps. The experimental studies indicates that the existing prototype can be developed as a competitive alternative for imaging in radiation therapy.

<p>This dissertation consists of two chapters studying monetary and fiscal policy. In the first chapter, I study the welfare benefits and costs of increased central bank transparency in a dynamic model of costly information acquisition where agents can either choose to gather new costly information or remember information from the past for free. Information is costly to acquire due to an agent's limited attention. Agents face an intratemporal decision on how to allocate attention across public and private signals within the period and an intertemporal decision on how to allocate attention over time. The model embeds a coordination externality into the dynamic framework which motivates agents to be overly attentive to public information and creates the possibility of costly transparency. Interestingly, allowing for intratemporal and intertempral tradeoffs for attention amplifies (attenuates) the benefits (costs) of earlier transparency whereas it attenuates (amplifies) the benefits (costs) of delayed transparency. </p><p>The second chapter, co-authored with Barbara Rossi and Atsushi Inoue, studies the empirical effects of unexpected changes in government spending and tax policy on heterogeneous agents. We use data from the Consumption Expenditure Survey (CEX) to estimate individual-level impulse responses as well as multipliers for government spending and tax policy shocks. The main empirical finding of this paper is that unexpected fiscal shocks have substantially different effects on consumers depending on their age, income levels, and education. In particular, the wealthiest individuals tend to behave according to the predictions of standard RBC models, whereas the poorest individuals tend to behave according to standard IS-LM (non-Ricardian) models, due to credit constraints. Furthermore, government spending policy shocks tend to decrease consumption inequality, whereas tax policy shocks most negatively affect the lives of the poor, more so than the rich, thus increasing consumption inequality.</p> / Dissertation

This study is a contribution to the development of the theory of bank portfolio selection behaviour. A central idea in the study is that this behaviour can be explained to a large extent by liquidity considerations which banks make in view of the partly uncontrollable and partly unforeseeable fluctuations which occur in their deposits and to a certain extent, also in their loans. This idea was presented originally in a now-classic article by Edgeworth entitled "The Mathematical Theory of Banking" which was published in 1888 and which has been the basis for a number of studies published in the past few decades. In the present study Edgeworth1s approach is developed in a number of different respects. At the same time, it is integrated with two other significant theory formations regarding banks' portfolio selection behaviour: (i) the well-known theory of the bank system's credit multiplier process which is found in many textbooks, and (ii) the related theory of the adjustment in the bank system's free reserves. Special attention is given to the effects of monetary policy. / digitalisering@umu

This paper uses U.S. macroeconomic data drawn from 2001 to 2010 in order to test for the operation of a credit channel of monetary transmission. Using a combination of a VAR and ADL time series frameworks, evidence is found for the impairment of the credit channel during the crisis period relative to the period which preceded it. Evidence is also found against the presence of a "credit crunch" during the crisis, and supporting evidence is found for the existence of a "credit trap." This analysis indicates a significant role for credit market imperfections in the transmission of monetary policy, and holds policy implications for the potential impact of future monetary expansions conducted in the setting of a financial crisis.