Spectrum sensing plays a key role for radio resource awareness in cognitive radio. To enhance the capabilities of cognitive radio nodes, exploiting the spatial resource in addition to frequency and time re-sources seems reasonable. This thesis investigates the possibility of exploiting the spatial resources during sensing and transmission using sector antennas which is also termed as directional spectrum sensing and transmission. The measured radiation patterns from fabricated antenna and radiation patterns obtained from analytical expressions representing circular array of dipole are used for performance analysis. A ray tracer tool is used for modelling the urban environment as well as for wave propagation simulation. The power angular profiles obtained at different locations are further processed in MATLAB using measured and analytical radiation patterns to evaluate the performance in terms of spatial opportunity and detection of weak primary signals. The results show that exploiting the spatial dimension in spectrum sensing using sector antennas increase the opportunities for secondary communication and also improves the detection of primary signals as compared with an omni-directional antenna. Additionally, directional sensing and trans-mission are studied together using analytical radiation patterns. The results show that the service probability as well as range of communica-tion increases with an increase in number of sectors but saturation is achieved when nine sectors are used, indicating that six sectors antenna is the optimum choice for exploring the spatial resource in cognitive radio in a typical multipath urban environment.

Investiga la relación no-lineal entre el crédito privado agregado del sector bancario y el producto interno bruto para Perú con data trimestral. Para el período 1994-2008, se examinó la existencia de diferentes regímenes que gobiernen ambas variables de manera independiente y conjunta, asociados a diferentes estados de la economía y cambios en el sistema financiero. Se utilizaron dos modelos de cambio de régimen, LSTAR y Markov Switching, porque permiten estimar parámetros cambiantes acorde a las diferentes etapas de la economía. Los resultados muestran que existen por lo menos dos regímenes, el primero de contracción y segundo de expansión, los cuales condicionan el comportamiento del crédito y el producto. / Rechearch the non-lineal relation among private credit and output in Peru with quarterly database. For the period 1994-2008, it was examined the existence of different regimes which govern both variables, isolated or together, associated with different states of the economy and change in the financial system. It utilizes Markov Switching models because it allows changing parameters estimated according to different regimes.

Conocer de qué manera las características del riesgo influye en la eficacia de las operaciones económicas y financieras de la empresa industrial en el Perú, es el principal objetivo; teniendo en cuenta su medida y coherencia, así como elevar el nivel de valoración de la empresa industrial. Asímismo, se determina de qué manera la estimación de resultados futuros de riesgo facilita la selección de activos (carteras) óptimos en la empresa industrial. / Our main is to get to know in what way the risk characteristics influence the effectiveness of economics and financial operations in the industrial company in Peru; considering its measurement and coherency, as well as increasing valuation level on the industrial company. Additionaly, it is determine in what way the estimation of future risk results facilitates the optimous assets’selection (asset portfolio) in the industrial company.

The study examined organizational climate and turnover in the health sector of Ghana with particular reference to a case study on the country’s premier teaching hospital formally called Korle-Bu Teaching Hospital. In the light of high uncertainty in retention of healthcare workers in Ghana, despite the several interventions of government in providing incentives and infrastructure, the issue of employee turnover has attracted academic interest among several researchers globally and locally. Most researches on turnover related issues in the healthcare sector of Ghana have focused on the influence of employees’ overall job satisfaction. However, none has been able to neither explain nor investigate the influence of potent psychological features of the workplace on turnover. This study undertook a comprehensive review of the current state of employees’ turnover intentions in relation to the organizational climate and other working conditions prevalent at the Korle-Bu Teaching Hospital. The study was guided by the hypothesis that climate factors will emerge as a significant predictor of employees’ turnover intentions. A sample size of 80 employees was used for the study. Correlation and multiple regression analysis were used to analyze data obtained with a Likert scale designed questionnaire. The results of the study indicate that stress and organizational pride are the most proximal factors to employees’ intentions to quit. Further analysis identified influences on stress and organizational pride and pointed to management priorities for reducing employee turnover.

In this thesis, we propose a scheduling problem for the downlink of a single cell system with multiple sectors. We formulate an optimization problem based on a generalized round robin scheme that aims at minimizing the cycle length necessary to provide one timeslot to each user, while avoiding harmful interference. Since this problem is under-constrained and might have multiple solutions, we propose a second optimization problem for which we try to find a scheduling that minimizes the cycle length while being as efficient as possible in resource utilization. Both of these problems are large integer programming problems that can be solved numerically using a commercial solver, but for real time use, efficient heuristics need to be developed. We design heuristics for these two problems and validate them by comparing their performances to the optimal solutions.

Högskolan Kristianstad har gamla anor med utbildningar från mitten av 1800-talet men grundades först 1977 i sin nuvarande form. De sista 4-5 åren har högskolan haft planer på att göra en omstrukturering. Förändringsarbetet tog fart förra året och vi blev intresserade av att skriva om de förändringar som pågick. Syftet med uppsatsen var att analysera förändringsprocessen vid Högskolan Kristianstad, samt undersöka hur de anställda påverkades av den. Vi valde att göra intervjuer med de anställda för att få inblick om hur de upplever sin situation. Våra frågeställningar var: Vad var de anställdas syn på omorganisationen? Vad har de anställdas förväntningar varit under processens gång?  Vad har de anställdas farhågor varit under processens gång och vilka motstånd har uppkommit från de anställda under processens gång? Våra slutsatser är bland annat att en förändring är nödvändig på Högskolan Kristianstad, att skolan behöver en stark och tydlig ledning, att det hade varit bra om ledningen hade ett bredare underlag om förändringar i en akademisk miljö. Eftersom det redan finns en färdig plan för hur Högskolan Kristianstad ska se ut år 2012 så är det extra viktigt att ledningen drar lärdom av det förändringsarbete som nu pågår.

In this thesis, we construct a mathematical model for Sectorized FFR Networks (SFN). In SFN, frequency allocation adopts FFR (Fractional Frequency Reuse), which divides the frequency into two parts: the super group (Sup-G) and the regular group (Reg-G). Since the frequency allocations of Sup-G and sectors overlaps each other, and the same frequency band is used by two Sup-G in two different BS, when the radius of Sup-G is too large, interferences will occur among the adjacent BS. In our mathematical model, given different environmental parameters (number of sector, number of MS, strength of power), we can compute the system capacity by varying the radius of Sup-G and the various environmental parameters. In practical applications, since the number of MS becomes smaller in the cellular edge and it increases rapidly in the cellular center, Gaussian distribution is more adequate to model the distribution of MS. Thus, in the calculation of interference, we take the integration of the path loss multiplied by the transmission power and the MS density. Finally, through the SINR and Shannon Capacity formula, we can derive the overall system capacity. From the mathematical model, we can achieve a ratio of Sup-G radius and cellular radius. With this radius ratio, an MS can have about the same capacity regardless of the position in the FFR network. Otherwise, an MS may get very different capacity when it moves to the cellular edge or sometimes it appears in the cellular center. Additionally, from the mathematical model, we can analyze the interferences and system capacity for different numbers of sectors.

Abstract The purpose of this paper is to use a dynamic view of systems of innovations in order to explore the roles of a public sector in identifying innovative opportunities introduced by new technologies and new high tech products and shaping the competitive advantages of Sweden. This thesis is limited as to the field of good products in the mobile communication industry. Basing that if a country can specialize, put and allocate all of its efforts in the mobile telecommunication industry, the country could possibly enjoy better economic growth and competitive advantages comparing with other countries specialized in other less promising industries. While deducing contemporary innovation theories, the conflicts and contradictions are notified between the proactive roles assumed by the government sector in creating innovations and traditional views concerning the appearing of radical innovations. According to those theories, the public agencies are proposed to assume more responsibilities in creating innovations, while the sources of innovations are merely considered as a result of ¡§chance¡¨ or ¡§serendipity¡¨. A proactive view in articulating the roles of the government agencies is illustrated in this thesis in the respects of the intentions of technical developments. Using NMT and GSM standard development process as empirical cases, it is concluded that circumstances are favorable for radical innovations where a competent public sector agency with visions places procurement orders based on transparent competition and open standards or technical specifications, coupled with a competitive producer market. In the meanwhile, while working closely together with international standardization institutions and taking part in R&D projects, the pubic sector plays a different role, namely, as an entrepreneur, a catalyst, and a competent user, in the innovation process of the mobile telecommunication development. Key Words: Innovation, Sweden, Mobile Telecommunication, Public Sector, Ericsson, NMT, GSM

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