Vehicles searching for on-street parking create environmental and economic externalities through increasing network traffic flow and congestion, heightening pollutant emission levels, creating additional noise, giving rise to time delays for through vehicles, and leading to potential safety hazards caused by vehicles manoeuvring into or out of on-street spaces. Despite extensive negative impacts on individual drivers and on society, parking search is an under-researched area, particularly in more recent years and within the UK. Furthermore, current statistical modelling techniques applied to parking search time have not utilised a more comprehensive analysis in which hierarchically structured data on multiple levels could be addressed. The aim of this thesis, therefore, is to investigate and compare the factors that influence drivers urban on-street parking search time and its policy implications. A mixed methods approach was applied that comprised qualitative interviews conducted with local government authority Council Officers and a quantitative revealed preference on-street parking survey (sample size, 1,002 observations) undertaken in four cities in the East Midlands region of the UK in order to obtain individual driver-level socio-economic and other parking related factors that may influence parking search time. Statistically significant variables for each of the cities were identified by employing separate linear regression models. A multilevel mixed-effects model in which drivers (Level 1) are nested within streets (Level 2) was then applied to the pooled dataset. Significant factors in the multilevel (street level) model were identified as: time of arrival at a parking place (for which every time period after the 07:00-07:59 reference case indicated increased search time); parking habit; parking tariff; the number of parking places previously visited (on the same trip); trip time from origin to parking place; area type; trip purpose; weather; vehicle type; and walking time from a parking place to a destination. Comparison of the factors that influence parking search time revealed important differences in statistically significant variables and coefficient values between the single-level and multilevel regression modelling approaches. Policy recommendations based upon the findings of the parking survey, modelling analysis, and further interviews conducted with local authority Council Officers, focus around time of arrival at a parking place, area type, parking charges and the potential technological advances that, if implemented, could have a considerable effect on parking search times within urban areas. Robust data collection and subsequent monitoring of parking search activity within each city should be undertaken in order to provide an evidence base which would support the introduction of future policy measures to reduce parking search activity.

Knowledge workers (KW), as important individual agents who embody, exchange, create and exploit knowledge, contribute to regional competitiveness and growth. To attract and retain them in a region, it is necessary to have a better understanding of their fundamental spatially-related behaviors including residence, workplace, and commute choices. In this study, we depart from a perspective of knowledge typology (analytical-synthetic-symbolic knowledge base) to investigate the heterogeneity of knowledge workers' residence, workplace, and commute choices. The case study was conducted in the metropolitan region of Munich. Various types of data are integrated: structural statistical and individually-based web-survey data; individuals' actual choices and their assessment of importance for each criterion; positional and relational data. We find that symbolic Advanced-Producer-Services (APS) workers tend to reside in central areas and use public transport or active modes to commute. In contrast, synthetic high-tech workers are found in relatively peripheral areas and depend more on cars to reach their workplaces. The spatially-related choices of analytical high-tech and synthetic-APS workers are positioned in between symbolic APS-workers and synthetic high-tech workers. We reach three conclusions: Firstly, the features of the knowledge base are evident in the spatial choices of knowledge workers. Secondly, there is a consistency of characteristics between interrelated spaces surrounding residence, workplace, as well as along the commute path of knowledge workers. Lastly, while the influence of the knowledge base has to be weighed against socio-demographic factors, different groups of knowledge workers clearly display distinct choices of residential location and commute mode. These conclusions may provide insights for urban planners and policy-makers regarding the attraction and retention of knowledge workers.

In this article, we consider the portfolio selection problem as a Bayesian decision problem. We compare the traditional mean–variance and mean–variance–skewness efficient portfolios. We develop bi-level programming problem to investigate the market’s preference for risk by using observed (market) weights. Numerical experiments are conducted on a portfolio formed by the 30 stocks in the Dow Jones Industrial Average. Numerical results show that the market’s preferences are better explained when skewness is included.

This study used focus groups and surveys to provide a comprehensive evaluation of the Regional Traveler Information Center (RTIC) at UMass Amherst. The evaluation was completed by obtaining the awareness, usage, and perceived effectiveness of RTIC’s information by residents in the Pioneer Valley. It was found that awareness of RTIC is limited due to its lack of advertisement. Usage is focused primarily on its webcams and advisory information. Surveys showed that participants perceive RTIC to be useful, even though they may never have seen the information before (the survey provided a chance for them to become familiar with the service). Revealed preference data were collected regarding the travelers' most memorable instances where real-time traffic information was provided. A binary logit model of a traveler's switch decision (route, departure time, mode, destination, trip cancellation, or combinations of them) with real-time traffic information was specified and estimated. It was found that travelers have an increasing tendency to switch away from the original option when the resulting delay caused by congestion increases. Receiving congestion and crash information also provided a tendency to take an alternative travel method. It was found that males tend to switch more often than females, and young individuals switch less often.

This revealed preference study estimates the implicit value associated with owning a home along a river and tree coverage of riparian areas along rivers. The setting of this study is Ashe and Watauga Counties in Northwestern North Carolina and the two rivers that flow through those counties: New River and Watauga River. House sales form the basis of the hedonic models used to value these environmental characteristics. Homes that border a river sell for at least $28,000 more than otherwise similar homes that do not border a river. Riparian area tree coverage positively impacts river-bordering house prices, but only to a certain point. The results of this study are important for environmental organizations in this region working to safeguard the New and Watauga Rivers through riparian buffer installation and protection. / Master of Science / This study describes homeowner values of owning a home near a river, along with values associated with tree coverage of riparian areas along rivers. The setting of this study is Ashe and Watauga Counties in Northwestern North Carolina and the two rivers that flow through those counties: New River and Watauga River. Using home sales data, models estimate the value of two environmental characteristics home properties. This research found that homes bordering a river sell for at least $28,000 more than otherwise similar homes that do not border a river. Having any amount of tree coverage up to 90% tree coverage in a riparian area increases home sale prices, therefore homeowners positively value tree coverage in riparian areas to a point. Tree coverage in riparian areas is beneficial for the protection of rivers and river-dependent wildlife. The results of this study are important for environmental organizations in this region working to safeguard the New and Watauga Rivers through riparian buffer installation and protection.

<p> Dramatic advances over the past decade have occurred in the use of cryogenic electron microscopy (cryoEM) to elucidate the structures of macromolecules at atomic resolution. Unfortunately, the sample preparation process is one of the most time-consuming and empirical methods in the cryoEM workflow. Each sample must be tediously optimized to resolve issues with particle aggregation, ice quality, particle orientation, and particle density to enable high-resolution reconstruction analysis. Post-polymerization modifications of synthetic aqueous bottlebrushes offer a promising approach to streamline the workflow for cryoEM sample preparation. Our approach utilizes synthetic bottlebrush materials comprised of flexible polymer scaffolds bearing grafted side-chains, armed with high affinity ligands at the distal termini of the grafted polymers along the polymer core. Development of water-soluble one-dimensional (1D) synthetic bottlebrush polymers has led to new advancements in the biomaterials, antimicrobial, nanomedicine, and responsive materials fields. These synthetic bottlebrush materials are favorable as they confer properties that linear polymers and small molecules cannot achieve. Moreover, structural manipulations employed during post-polymerization processes can afford bottlebrush polymers with distinguishable topologies for advanced functions. These 1D constructs can be synthesized by atom transfer radical polymerization (ATRP), reversible addition- fragmentation chain-transfer polymerization (RAFT), ring-opening polymerization (ROP), cationic ring-opening polymerization (CROP), anionic ring-opening polymerization (AROP) or ring opening metathesis polymerization (ROMP). The chemical composition of the molecule, number of monomer repeats, grafting density and topology influence the morphology and function of polymer brushes. Elongated, vesicular or micellar morphologies can be specifically tuned for the desired application of the material. The morphology of the polymers can also be manipulated by concentration effects. The morphologies of amphiphilic bottlebrush materials specifically, can typically be influenced by structural topology, solvent choice, or external conditions. ROMP is a living polymerization mechanism that can suffer from catalytic backbiting, causing a loss of livingness. The synthesis of aqueous bottlebrush polymers and the comparison of morphologies via AUC, DLS, AFM and TEM will be presented in this dissertation. The synthetic amphiphilic bottlebrush polymer family presented suffered a loss of livingness and ultimately displayed distinct morphologies, relative to chemical composition, solvent, and ultimately polymerization time. Post-polymerization 11 modifications such as backbone hydrolysis and single-walled carbon nanotube complexation promoted even more unique morphologies of bottlebrushes. These synthetic materials indicate use as promising reagents for cryoEM sample preparation.  </p>

Die vorliegende Studienarbeit beschäftigt sich mit der Fragestellung, inwiefern sich Revealed-Preference-Daten aus der deutschen Mobilitätsbefragung "Mobilität in Städten" SrV 2008 dazu eignen, um basierend auf denen im Datensatz enthaltenen Wegen Verkehrsmittelwahlmodelle zu schätzen. Dazu wurden Wegedaten aus der Befragung verwendet, und die Wahlalternativen mit Hilfe der Google Directions API rekonstruiert. Mit den rekonstruierten Variablen Reisezeit und Reisekosten sowie verschiedenen sozioökonomischen und externen Variablen aus SrV 2008 wurden verschiedene Wahlmodelle geschätzt. Durch schrittweises Hinzufügen der Variablen konnte das Modell immer weiter verbessert werden. Wie zu erwarten, erwiesen sich dabei die Reisezeit und die Reisekosten als hoch signifikant. Von den restlichen Variablen waren jedoch lediglich das Geschlecht der befragten Person sowie die Wettersituation zum Zeitpunkt der Wahlentscheidung signifikant. Für das finale Modell wurden Zeitkostensätze errechnet und mit verschiedenen europäischen Studien verglichen. Die errechneten Zeitkostensätze erwiesen sich dabei als plausibel. Die SrV-Daten eignen sich also für die Schätzung von Wahlmodellen. / The following thesis analyzes, if revealed preference data from the German mobility survey "Mobilität in Städten" SrV 2008 is suited to estimate mode choice models. For that purpose, trip data from the survey was used and the different choice alternatives were reconstructed with the Google Directions API. Several mode choice models were estimated with the help of the reconstructed variables travel time and travel costs plus several socioeconomic and external variables from SrV 2008. The variables were added to the model step by step, thereby the quality of the model improved. As expected, travel time and travel costs were highly significant. However from the remaining variables only the gender of the person and the weather at the time of the trip were significant. For the final model, values of time were calculated and these were compared with values from different European studies. The calculated values of time proved to be feasible. Therefore, SrV data is suited to be used for mode choice models.

The purpose of this paper was to examine the competitiveness of the South African sugar industry relative to the top ten exporters of the product, namely Brazil, Thailand, Netherlands, Mexico, China, Germany, Canada, France, Belgium and the United States of America. Different techniques were used in the study to ensure that the main objective of the study was achieved. Three popular indices, namely the Balassa Revealed Comparative Advantage (RCA#) Index, the Net Export Index (NXi) and the Relative Revealed Comparative Trade Advantage (RTA) Index were used to compare the competitiveness of the top ten sugar exporting countries including South Africa. The Trade Potential Index was also applied in the study to investigate markets that South Africa could use to increase its exports. Time series data collected on the trade map and the Food and Agricultural Organization of the United Nations were used for the analysis of the markets by using an Excel spreadsheet. The results of the study showed that South Africa has a trade competitive advantage against the majority of the countries considered. South Africa's competitive performance was surpassed by that of Brazil, which was the strongest trader of sugar, followed by Thailand and China. The remaining seven countries (Mexico, Belgium, Netherlands, Canada, Germany, USA and China) were all exceeded by the South African sugar industry. The top potential markets that South Africa could exploit to increase its exports were identified with the use of the Trade Potential Index (TPI). The countries that were identified were selected by calculating the scores, comparing tariffs imposed by these markets to the exporters of sugar and looking at the concentration of the markets that supply these potential markets. The United States of America, Lesotho, Democratic Republic of Congo, Malawi and Egypt were identified as the top five countries that South Africa could exploit for its sugar exports. South Africa has trade agreements with the majority of these countries which assist the country in obtaining preferential agreements when exporting its products to these countries. Recommendations were made that could help the sugar industry to grow its competitiveness. / Inhloso yaleliphepha bekukuhlola kuncintisana kwemboni yashukela yaseNingizimu Afrika nayicatsaniswa nebatfumeli ngaphandle labasembili labalishumi balomkhicito, lekuyiBrazil, iThailand, iNetherlands, iMexico, iChina, iGermany, iCanada, iFrance, iBelgium ne-United States of America. Kusetjentiswa emasu lahlukene kulesifundvo kucinisekisa kutsi inhloso lenkhulu yesifundvo iyaphunyelelwa. Kusetjentiswe ema-indice, lekuyi-Balassa Revealed Comparative Advantage (RCA#) Index, i-Net Export Index (NXi) kanye ne-Relative Revealed Comparative Trade Advantage (RTA) Index kucatsanisa kuncintisana kwalamave lasembili lalishumi lakhicita shukela kufaka ekhatsi eNingizimu Afrika. I-Trade Potential Index nayo isetjentisiwe kulesifundvo kuphenya timakethe letingasetjentiswa yiNingizimu Afrika kute ikhulise kutfumela ngaphandle kwayo lomkhicito washukela. Idatha yeluchungechunge lwesikhatsi legcogcwe kulibalave lekuhwebelana kanye naseNhlanganweni Yekudla Neyetekulima yaMhlab'uhlangene isetjentisiswe kuloluhlatiyo lwetimakethe ngekusebentisa si-spreadsheet se-Excel. Imiphumela yesifundvo ikhombise kwekutsi iNingizimu Afrika inekusitakala ngekuncintisana ekuhwebeni nayicatsaniswa nelinyenti lalamave lamanyenti lahlatiyiwe. Kusebenta kwekuncintisana kweNingizimu Afrika kundlulwe kusebenta kweBrazil, lebeyingumhwebi lomkhulu washukela, ilandzelwe yiThailand kanye neChina. Lamave lasikhombisa lasele (iMexico, iBelgium, iNetherlands, iCanada, iGermany, i-USA neFrance) onkhe andlulwe yimboni yashukela yaseNingizimu Afrika. Timakethe letingaba khona letiphambili leti iNingizimu Afrika ingatisebentisa kukhulisa kutfumela ngaphandle kwayo tibonwe ngekusebentisa iTrade Potential Index (TPI). Emave laboniwe akhetfwe ngekubala imiphumela, kucatsanisa ematharifu lafakwe nguletimakethe kubatfumeli bangaphandle bashukela nekubuka kulokucocana kwetimakethe lephakela letimakethe letingaba khona. I-United States of America, iLesotho, iDemocratic Republic of Congo, iMalawi ne-Egypt abonwe njengemave lasembili lasihlanu langasetjentiswa yiNingizimu Afrika kutfola ngaphandle shukela wayo. INingizimu Afrika inetivumelwano tekuhwebelana nelinyenti lalamave lokusita lelive ekutfoleni tivumelwano tekubekwa ngembili nangabe kutfunyelwa ngaphandle imikhicito yayo kulamave. Tiphakamiso letingasita imboni yashukela kukhulisa kuncintisana kwayo tentiwe. / Inhloso yalo mbhalo wocwaningo kwabe kuwukucubungula nokuhlaziya amandla okuncintisana ngempumelelo kwemboni kashukela yaseNingizimu Afrika uma iqhathaniswa namazwe ayishumi ahamba phambili emhlabeni ekuthumeleni imikhiqizo kashukela emazweni angaphandle, okuyi-Brazil, Thailand, Netherlands, Mexico, China, Germany, Canada, France, Belgium kanye neMelika (USA). Kulolu cwaningo kwasetshenziswa izindlela ezihlukahlukene ngenhloso yokuqinisekisa ukufezekiswa kwenjongo enkulu yocwaningo. Kwasetshenziswa izinkomba-simo ezintathu ezidumile futhi okuyizona ezisetshenziswa kakhulu, okuyi-Balassa Revealed Comparative Advantage (RCA#) Index, Net Export Index (NXi) kanye ne-Relative Revealed Comparative Trade Advantage (RTA) Index ukuqhathanisa amandla okuncintisana ngempumelelo kwamazwe ayishumi ahamba phambili emhlabeni ekuthumeleni ushukela emazweni angaphandle, kubandakanya neNingizimu Afrika. I-Trade Potential Index yasetshenziswa futhi nayo kulolu cwaningo ukuphenya nokucubungula izimakethe ezingasetshenziswa yiNingizimu Afrika ukukhulisa inani lemikhiqizo yayo ethunyelwa emazweni angaphandle. Idatha eqoqwe ochungechungeni lwamaqophelo alandelana ngokwesikhathi ebalazweni lokuhwebelana kanye naseNhlanganweni Yokudla NezolimoyeNhlangano Yezizwe yasetshenziselwa ukuhlaziya izimakethe ku-Excel spreadsheet. Imiphumela yocwaningo yabonisa ukuthi iNingizimu Afrika isesimweni esikahle futhi inamandla angcono okuncintisana ngempumelelo kwezohwebo uma iqhathaniswa neningi lamazwe acutshungulwayo. Amandla eNingizimu Afrika okuncintisana ngempumelelo adlulwa yilawo e-Brazil, okuyizwe elinamandla kakhulu futhi elihamba phambili kwezokuhwebelana ngoshukela, kulandele i-Thailand kanye ne-France. Imboni kashukela yaseNingizimu Afrika inamandla angaphezulu kwawo wonke lawa amanye amazwe asele ayisikhombisa (okuyi-Mexico, Belgium, Netherlands, Canada, Germany, USA kanye ne-China). Amazwe ahamba phambili angasetshenziswa yiNingizimu Afrika ekukhuphuleni umthamo wemikhiqizo yayo ethunyelwa emazweni angaphandle ahlonzwa ngokusebenzisa i-Trade Potential Index (TPI). Lawo mazwe ahlonziwe akhethwe ngokubala inani lamaphuzu, ukuqhathanisa intela yempahla ekhokhiswa yilawo mazwe emazweni angaphandle athumela ushukela kanye nokubheka ubuningi bamazwe athumela imikhiqizo yawo kulawo mazwe angasetshenziswa yiNingizimu Afrika ukukhulisa umthamo wemikhiqizo yawo ethunyelwa emazweni angaphandle. I-USA, Lesotho, Democratic Republic of Congo, Malawi kanye ne-Egypt ahlonzwa njengamazwe aphuma phambili iNingizimu Afrika engathumela kuwona ushukela. INingizimu Afrika inezivumelwano zokuhwebelana neningi lalawa mazwe, okuyizivumelwano eziyilekelelayo ekutholeni izivumelwano ezizokwenza ibhekelelwe kangcono futhi icatshangelwe uma ithumela imikhiqizo yayo kulawa mazwe angaphandle. Kwenziwa izincomo ezingayilekelela imboni kashukela ukuthi ikwazi ukukhulisa amandla ayo okuncintisana ngempumelelo. / Agriculture and  Animal Health / M. Sc. (Agriculture)

Die vorliegende Studienarbeit beschäftigt sich mit der Fragestellung, inwiefern sich Revealed-Preference-Daten aus der deutschen Mobilitätsbefragung "Mobilität in Städten" SrV 2008 dazu eignen, um basierend auf denen im Datensatz enthaltenen Wegen Verkehrsmittelwahlmodelle zu schätzen. Dazu wurden Wegedaten aus der Befragung verwendet, und die Wahlalternativen mit Hilfe der Google Directions API rekonstruiert. Mit den rekonstruierten Variablen Reisezeit und Reisekosten sowie verschiedenen sozioökonomischen und externen Variablen aus SrV 2008 wurden verschiedene Wahlmodelle geschätzt. Durch schrittweises Hinzufügen der Variablen konnte das Modell immer weiter verbessert werden. Wie zu erwarten, erwiesen sich dabei die Reisezeit und die Reisekosten als hoch signifikant. Von den restlichen Variablen waren jedoch lediglich das Geschlecht der befragten Person sowie die Wettersituation zum Zeitpunkt der Wahlentscheidung signifikant. Für das finale Modell wurden Zeitkostensätze errechnet und mit verschiedenen europäischen Studien verglichen. Die errechneten Zeitkostensätze erwiesen sich dabei als plausibel. Die SrV-Daten eignen sich also für die Schätzung von Wahlmodellen.:1 Einleitung 1 1.1 Vorstellung des Themas 1 1.2 Ziel dieser Arbeit 1 1.3 Gliederung dieser Arbeit 2 1.4 Wesentliche Ergebnisse 2 2 Theoretischer Hintergrund 3 2.1 Diskrete Wahltheorie 3 2.1.1 Deterministischer Nutzen 4 2.1.2 Stochastischer Störterm 5 2.1.3 Logit-Modell 6 2.2 Parameterschätzung 8 2.2.1 t-Test 9 2.2.2 Likelihood-Ratio Test 9 2.2.3 Likelihood-Ratio-Index 10 2.3 Datenquellen 10 3 Generierung eines RP-Datensatzes aus SrV-Daten 13 3.1 SrV 2008 13 3.2 Auswahl an Variablen und Datensätzen 13 3.3 Rekonstruktion der generischen Variablen 15 3.3.1 Google Directions API 15 3.3.2 Automatisierte API-Abfrage 16 3.3.3 Reisekosten 17 3.4 Erzeugter Datensatz 18 4 Modellentwicklung und Parameterschätzung 21 4.1 Entwicklung des Wahlmodells 21 4.2 Parameterschätzung mit Biogeme 24 4.3 Anwendung der Parameterschätzung auf die SrV-Daten 28 5 Diskussion der Modellergebnisse 33 5.1 Darstellung der Nutzeneinflüsse 33 5.2 Zeitkostensätze 35 5.3 Fehlerquellen 37 5.4 Fazit 38 Literaturverzeichnis 41 Datenquellen 45 Anhang 49 / The following thesis analyzes, if revealed preference data from the German mobility survey "Mobilität in Städten" SrV 2008 is suited to estimate mode choice models. For that purpose, trip data from the survey was used and the different choice alternatives were reconstructed with the Google Directions API. Several mode choice models were estimated with the help of the reconstructed variables travel time and travel costs plus several socioeconomic and external variables from SrV 2008. The variables were added to the model step by step, thereby the quality of the model improved. As expected, travel time and travel costs were highly significant. However from the remaining variables only the gender of the person and the weather at the time of the trip were significant. For the final model, values of time were calculated and these were compared with values from different European studies. The calculated values of time proved to be feasible. Therefore, SrV data is suited to be used for mode choice models.:1 Einleitung 1 1.1 Vorstellung des Themas 1 1.2 Ziel dieser Arbeit 1 1.3 Gliederung dieser Arbeit 2 1.4 Wesentliche Ergebnisse 2 2 Theoretischer Hintergrund 3 2.1 Diskrete Wahltheorie 3 2.1.1 Deterministischer Nutzen 4 2.1.2 Stochastischer Störterm 5 2.1.3 Logit-Modell 6 2.2 Parameterschätzung 8 2.2.1 t-Test 9 2.2.2 Likelihood-Ratio Test 9 2.2.3 Likelihood-Ratio-Index 10 2.3 Datenquellen 10 3 Generierung eines RP-Datensatzes aus SrV-Daten 13 3.1 SrV 2008 13 3.2 Auswahl an Variablen und Datensätzen 13 3.3 Rekonstruktion der generischen Variablen 15 3.3.1 Google Directions API 15 3.3.2 Automatisierte API-Abfrage 16 3.3.3 Reisekosten 17 3.4 Erzeugter Datensatz 18 4 Modellentwicklung und Parameterschätzung 21 4.1 Entwicklung des Wahlmodells 21 4.2 Parameterschätzung mit Biogeme 24 4.3 Anwendung der Parameterschätzung auf die SrV-Daten 28 5 Diskussion der Modellergebnisse 33 5.1 Darstellung der Nutzeneinflüsse 33 5.2 Zeitkostensätze 35 5.3 Fehlerquellen 37 5.4 Fazit 38 Literaturverzeichnis 41 Datenquellen 45 Anhang 49

Este trabalho tem como objetivo analisar a competitividade das exportações brasileiras de manga e de uva no mercado internacional no período de 1989 a 2005. Para tanto, utilizou-se o modelo de Constant Market Share (CMS) e o modelo de Vantagem Comparativa Revelada (VCR) para evidenciar os principais fatores responsáveis pela rápida expansão das exportações nacionais para esses dois produtos, além de realizar uma análise comparativa entre as duas culturas selecionadas. O primeiro modelo busca analisar as causas de variação da quantidade (ou valor) exportada de um produto pelo país em questão em relação ao tempo, gerando três dimensões explicativas para a variação das exportações: o efeito dimensão, o efeito distribuição e o efeito competitividade. O efeito dimensão mostra como o crescimento das exportações mundiais afetou o crescimento das exportações do país analisado. O efeito distribuição refere-se às exportações para países de maior ou menor dinamismo. Por resíduo, descontando-se os demais efeitos temos o termo competitividade.Para a geração dos resultados foi necessária a sub-divisão do período de análise em três grupos trienais: 1989/1990/1991, 1994/1995/1996 e 2003/2004/2005.O modelo de Vantagem Comparativa Revelada parte do pressuposto de que o país em questão tende a se especializar nas exportações de produtos que ofereçam vantagens competitivas. Para tanto, o indicador deve apresentar um valor superior a 1 para os produtos competitivos, evidenciando que a participação do produto em questão na pauta do país analisado é superior à participação do país no mercado global geral. Diferentemente do CMS, os indicadores de Vantagem Comparativa Revelada (VCR) nas exportações de um produto podem ser calculados com freqüência anual. O resultado do modelo de Constant Market Share para manga, referente ao primeiro sub-período de análise, mostra que o significativo aumento das exportações brasileiras de manga foi fortemente influenciado pelo crescimento do mercado mundial, seguido pelo efeito competitividade e destino das exportações. Para o segundo subperíodo, o efeito de maior significância foi a competitividade, seguido pelo efeito crescimento do mercado mundial e destino das exportações. Para a uva, o resultado referente ao primeiro sub-período de análise mostra que o significativo aumento das exportações brasileiras dessa fruta foi fortemente influenciado pelo efeito destino das exportações, seguido pelo efeito competitividade e crescimento do mercado mundial. Para o segundo sub-período, os resultados apontam a competitividade como principal fator responsável pelo aumento das exportações brasileiras, seguido pelo efeito crescimento do mercado mundial. O efeito destino das exportações apresentou valor negativo. Para o caso da manga, foram observados altos valores para o indicador de Vantagem Comparativa Revelada, especialmente para o período após 1993. Diferentemente dos resultados apresentados para a manga, as exportações de uva revelam vantagem comparativa apenas no final do período analisado (depois de 2002). / This paper has the main purpose of analyzing competitiveness of Brazilian exports of mangoes and grapes in the international market between 1989 and 2005. Constant Market Share and Revealed Comparative Advantage were used to obtain the main factors that could explain the fast growth of Brazilian exports of the chosen fruits, doing a comparative analysis between these fruits. The first model tries to analyze the reasons of variation in the quantity (or value) of a product exported by the current country related to the time, generating three dimensions: the effect dimension, the effect distribution and the effect competitiveness. The effect dimension shows how the growth of the world exports affected the growth of the current country\'s exports. The effect distribution relates to exports to countries of bigger or smaller dynamism. As a result, discounting the other effects we have the term competitiveness. To generate the results it was necessary to have the sub-division of the analyzed period into three triennial groups: 1989/1990/1991, 1994/1995/1996 and 2003/2004/2005.The Revealed Comparative Advantage model considers that a country tends to specialize itself in exporting products that offer competitive advantages. Thus, the indicator must submit a value higher than 1 for competitive products, showing that the product participation in a country is superior to the country participation in the global market. Different from Constant Market Share (CMS), Revealed Comparative Advantage indicators of exports can be calculated with annual frequency. The Constant Market Share model result for mangoes, referring to the first sub-period analysis shows that the significant increase in Brazilian exports of mangoes was strongly influenced by the growth of the world market, followed by the competitiveness effect, and the destination of exports. For the second sub-period, the most significant effect was the competitiveness, followed by the growth of the world market and the destination of exports. Considering grapes, the result referring to the first sub-period analysis shows that the significant increase in Brazilian grapes exports was strongly influenced by the effect \"exports destination\", followed by the effect competitiveness and the world market\'s growth. For the second sub-period, the results indicate competitiveness as the main factor responsible for the increase of the Brazilian exports, followed by the growth of the world market. The effect \"exports destination\" showed a negative value. For the Revealed Comparative Advantage (RCA) model, the mango case results showed a high revealed comparative advantage, especially after 1993. The grapes´ results show a comparative advantage only at the end of the period, when, from 2002 on there was a trend of grape consolidation as a competitive product in the international market, though on a distant level from mangoes.