Capacity Study of Statistical Multiplexing for IP Telephony

Transmitting telephone calls over the Internet causes problems not present in current telephone technology such as packet loss and delay due to queueing in routers. In this undergraduate thesis we study how a Markov modulated Poisson process is applied as an arrival process to a multiplexer and we study the performance in terms of loss probability. The input consists of the superposition of independent voice sources. The predictions of the model is compared with results obtained with simulations of the multiplexer made with a network simulator. The buffer occupancy distribution is also studied and we see how this distribution changes as the load increases

IN THE SHADOW OF CHINA: TRADE AND GROWTH IN LAO PDR

The rapid integration of China into the global economy has profoundly altered external economic conditions for its neighbors and the wider developing world. This study explores the effects on Laos, a small developing country on the fringe of the Chinese market. The Lao case captures both global effects transmitted across the world market and a regional impact that may be limited to countries located close to China. Based on unique trade and household data-sets, the study identifies three main effects of China’s growth on the Lao economy: (i) an increased demand for exports of primary commodities to the Chinese market; (ii) increased inflows of Chinese manufactured goods competing with domestic Lao production; and (iii) border effects in northern Laos where low transaction costs have allowed even the poorest households to participate in exports to China. The first and second of these effects are expected to apply to most developing countries, whereas the third is unique to developing countries located close to the Chinese market. In the long run, it is possible that increasing wages and a gradual reduction of the Chinese surplus of unskilled labor will create new opportunities for labor intensive industry in other developing countries, but the short run strategies of many countries should probably focus on gradual upgrading of resource based industries.Laos; exports; FDI; income distribution

REGIONAL DEVELOPMENT IN LAO PDR: GROWTH PATTERNS AND MARKET INTEGRATION

Lao PDR has shown a strong record of economic growth and poverty alleviation since the early 1990s. Yet, the pace of economic development has varied significantly between different parts of the country - the rate of growth was initially faster in more developed areas, but after the mid-1990s growth has been stronger in poorer rural areas. Here it is shown that this pattern of regional development has been driven by the nature of market integration. This is highlighted in three case studies covering: (i) the effect of transport infrastructure and local institutions on domestic consumer good markets; (ii) the process of regional integration with neighboring countries; and (iii) the ability of Lao producers to compete on the world market for coffee.Laos; Lao PDR; regional development; market integration; infrastructure

DETERMINANTS OF POVERTY IN LAO PDR

Lao PDR has been relatively successful in raising incomes and reducing poverty since the early 1990s. However, the gains in terms of poverty reduction are unevenly distributed across regions and population groups. This paper uses a detailed household survey data set to examine the determinants of income and poverty in Lao PDR. The results suggest that household size, dependency ratios, education, and access to agricultural inputs are among the main determinants of per capita consumption. In addition, geography and ethnicity matter. A closer analysis of the role of ethnicity suggests that the higher poverty incidence among minority households is due to their limited access to productive resources rather than lower efficiency in resource use. The paper also proposes some elements for a poverty reduction strategy for Lao PDR.Lao PDR; Laos; development; poverty; household; ethnic minorities

Dimensioning Links for IP Telephony

Transmitting telephone calls over the Internet causes problems not present in current telephone technology such as packet loss and delay due to queueing in routers. In this undergraduate thesis we study how a Markov modulated Poisson process is applied as an arrival process to a multiplexer and we study the performance in terms of loss probability. The input consists of the superposition of independent voice sources. The predictions of the model is compared with results obtained with simulations of the multiplexer made with a network simulator. The buffer occupancy distribution is also studied and we see how this distribution changes as the load increases

All about the marine/sea ice diatom Nitzschia lecointei

Generally, in terms of growth N. lecointei seems quite tolerant to changes in pH and pCO2, probably due to the fact that this species grows in an environment with large seasonal variations in the carbonate system. However, increased pCO2 resulted in physiological changes that may have important ecological consequences, such as cellular stoichiometry. For instance, we observed changes in carbon metabolism, and fatty acid content and composition, that did not affect the growth rate. When the experimental period was increased (194 days, ca. 60 asexual generations), we observed a small reduction in growth at 960 µatm pCO2 after 147 days. Carbon metabolism was significantly affected, resulting in higher cellular release of dissolved organic carbon. When studying the synergism between temperature (−1.8 and 2.5°C) and pCO2 (390 and 960 μatm), synergism was detected in growth rate and acyl lipid fatty acid content. Carbon enrichment only promoted (3 %) growth rate closer to the optimal growth, but not at the control temperature (−1.8°C). Optimal growth rate was observed around 5°C in a separate experiment. The total content of fatty acids was reduced at elevated pCO2, but only at the control temperature. PUFAs were reduced at high pCO2. When combining increased temperature and different salinity conditions, the growth rate was higher at 3°C than at -1.8°C. Salinity 10 clearly limited growth rate and the highest growth rates were found at salinity 20 and 35. In another experiment, high and low temperature together with treatments simulating ice formation and melting conditions were studied. Here, the highest levels of oxidative stress were found in low temperature and ice melting treatments, respectively. With respect to 9 weeks in the dark, cell numbers were higher at -1.5°C compared to 3°C, but when retrieved to light conditions, after one week higher cell numbers were observed at 3°C versus -1.5°C. Furthermore, cell numbers were lower when acetateUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Preferences for Short-Term Versus Long-Term Bonuses for Stock Investments

Performance-related bonuses in the finance sector are considered important tools to provide incentives. An example is that stock portfolio managers are awarded bonuses conditionally on their portfolios producing superior returns either relative to an index or equivalent funds. Concerns are however expressed that bonuses to portfolio managers are based on too short time intervals, which may impact negatively on the degree to which environmental and social factors are taken into account in investment decisions. The question addressed in this article is how bonus schemes can be designed so that delayed payouts will be equally motivating as short-term payouts. We have conducted two experiments to investigate preference for bonus payments that are paid out either frequently of infrequently. In Experiment 1 employing 27 undergraduates, preferences were measured for one certain long-term bonus versus four certain bonuses evenly distributed across time. A majority chose the short-term bonuses, and in order for a long-term bonus to be equally preferred the results showed that it needs to be approximately 40 percent higher than the four combined short-term bonuses. Experiment 2 employing another 36 undergraduates introduced uncertainty of outcomes which more accurately reflects the setting faced by stock investors. A four-year bonus is compared to four one-year bonuses. Uncertainty was the same, decreasing or increasing over the four years. The results showed that decreasing uncertainty made a majority prefer the four-year bonus to the added one-year bonuses. In conclusion, introducing uncertainty in choices concerning future outcomes is shown to reduce the extent to which future bonus outcomes are discounted relative to immediate bonus outcomes.Portfolio management; Performance-related bonus; Time discounting

Effective use of open source GIS in rural planning in South Africa

Syftet med denna studie är att ta fram en arbetsmetod för att samla in, lagra och visualisera geografisk data på ett enkelt och billigt sätt, samt att man når en stor målgrupp med denna geografiska data. Studien riktar sig främst till arbete som pågår i utvecklingsländer och i miljöer där man jobbar med begränsade resurser. Många organisationer som jobbar under dessa förutsättningar har inte råd att använda vanliga GIS-program som exempelvis ArcGIS för att visualisera den geografiska data. Många organisationer runt om i världen har tillgång till geografisk data, men de flesta av dessa har inte kunskap om hur denna kan visualiseras på ett smidigt sätt. Det kan dock vara viktigt att visualisera denna geografiska data för exempelvis en hjälporganisation. Anledningen till detta är att många av dessa organisationer jobbar med begränsade resurser och att de har någon form av prestationskrav gentemot sina finansiärer. Att kunna visualisera geografiska data från olika projekt runt om i världen skulle kunna vara ett sätt att informera berörda parter om hur arbetet går. Denna studie har ägt rum i Dukudukuskogen som ligger i KwaZulu-Natalprovinsen i Sydafrika. Den har varit finansierad av ett Minor Field Study-stipendium som ges ut av SIDA. Vi har samarbetat med ett lokalt konsultbolag vid namnet Enhanced Strategies. De är projektledare i Dukudukuskogen där ett 50-tal projekt, finansierat av regering och hjälporganisationer, äger rum. Syftet har varit att skapa en arbetsmetod som kan hjälpa till att visualisera dessa projekt och framstegen i området till berörda parter. En arbetsmetod har tagits fram med avsikt att vara så billig och att nå en så stor grupp människor som möjlig. För att minska kostnaderna i denna arbetsmetod har program baserat på öppen källkod använts och för att nå en stor målgrupp har program inom webb-baserat GIS använts i så stor utsträckning som möjligt. Den framtagna arbetsmetoden beskriver i sex olika steg hur man kan hämta, lagra och visualisera geografisk data på en hemsida. Resultatet av denna studie är, förutom den framtagna arbetsmetoden, tre stycken exempel där den framtagna arbetsmetoden används. Den första avser att vara en allmän karta över området där användaren själv väljer vad som ska visualiseras. Det andra exemplet beskriver hur geografisk data kan editeras över webben och då följdaktningen uppdatera en databas på distans. Det sista exemplet avser att beskriva hur arbetsmetoden kan användas för att visa framstegen i ett specifikt projekt.The purpose of this study is to develop a method on how to collect, store and visualize geographic data in an easy and inexpensive way, and to enable a wide audience to reach the information. The focus of this study is mainly on projects that are taking place in developing countries and in environments where one usually works with limited resources. Many of the organizations that are working in these environments cannot afford commonly used GIS programs like ArcGIS to visualize their geographic data. Organizations that are active in developing countries and are executing projects there have access to geographic data, but many of them have no knowledge on how to visualize these in a good way. For a nongovernmental organization (NGO) it could prove useful to visualize these geographic data for many purposes. One of the reasons for this is that the organizations are working with limited resources and they must be able to show results to their donors. Being able to visualize geographic data from various projects around the world could be one way to inform donors about the work progress. This study took place in Dukuduku forest located in KwaZulu-Natal in South Africa. It has been funded by a Minor Field Study, which is a scholarship given by the Swedish International Development cooperation Agency (SIDA). We also collaborated with a local consulting company named Enhanced Strategies. They are project managers within the Dukuduku forest where around 50 projects, funded by the government and NGOs, are taking place. The aim has been to create a workflow that can help to visualize these projects and the progress in the area to all the concerned parts. A workflow has been developed that describe in six steps how to gather, store and visualize geographic data. The intention with the workflow has been to enable development of cheap products that can reach a group of people as large as possible. Open source programs have been used to reduce the cost and Web GIS has been used to reach a wider audience. The results of this study are, in addition to the workflow, three examples that are based on the workflow. The first intends to be a basic map viewer where the user can decide which layers that should be visualized. The second example describes how geographic data can be edited through a web browser and consequently updating a database remotely. The last example is intended to describe how the workflow can be used for visualize the development in one specific project