<p>This study examines the relationship between land fragmentation and agricultural productivity in Vietnam, as well as the outcomes of land consolidation programs on productivity. Data from the Vietnam Household Living Standard Survey 2004 and data on the land consolidation process was used for the regression analysis. The results show weak correlations between fragmentation and productivity. Land fragmentation seems to be positively correlated to productivity due to more use of fertilizers and labour input. The communes that have consolidated their land are more productive, but this seems to be explained by initial differences in productivity. Our results suggest that there are no immidiate gains in land consolidation.</p>

This study examines the relationship between land fragmentation and agricultural productivity in Vietnam, as well as the outcomes of land consolidation programs on productivity. Data from the Vietnam Household Living Standard Survey 2004 and data on the land consolidation process was used for the regression analysis. The results show weak correlations between fragmentation and productivity. Land fragmentation seems to be positively correlated to productivity due to more use of fertilizers and labour input. The communes that have consolidated their land are more productive, but this seems to be explained by initial differences in productivity. Our results suggest that there are no immidiate gains in land consolidation.

Submitted by (ana.araujo@ufrpe.br) on 2016-08-17T12:42:21Z No. of bitstreams: 1 Vanessa Kelly dos Santos.pdf: 364306 bytes, checksum: 6c79d0925f6821655f91bcd3c8eb64af (MD5) / Made available in DSpace on 2016-08-17T12:42:21Z (GMT). No. of bitstreams: 1 Vanessa Kelly dos Santos.pdf: 364306 bytes, checksum: 6c79d0925f6821655f91bcd3c8eb64af (MD5) Previous issue date: 2009-03-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Diversity as a concept was first introduced by Williams in Fisher et al. (1943). Later, Good (1953, 1982) proposed a generalized index that included as special cases both Shannon’s and Simpson’s indices. Baczkowski et al. (1997, 1998) generalized the proposed generalization deriving the first four moments and then obtaining a distribution prior to the general index for Good (BACZKOWSKI et al., 2000). Therefore, is proposed a new generalization that, in addition to the indices the Shannon and Simpson as special cases, includes more general indices such as the unfamiliar (PATIL & TAILIIE, 1982). The moments of h(a,b,d) presented here extend the results presented in Baczkowski et al. and Bowman et al. for a class of diversity indices of more general and it is concluded then that while the distribution of index Shannon can be approximated by a Gaussian distribution, if any difference between abundance of species, to more general values of (a,b,d), it is suggested a distribution of type I as the most appropriated. The results are also consistent with those presented for real populations, as in Heip & Engels (1974), especially when it examines the index of Shannon. / A diversidade como um conceito foi inicialmente introduzida por Williams em Fisher et al. (1943). Mais tarde, Good (1953, 1982) propôs um índice generalizado que incluía como casos especiais os índices de Shannon e o de Simpson. Baczkowski et al. (1997, 1998) propuseram generalizar essa generalização derivando os quatro primeiros momentos e obtendo assim uma distribuição para o índice antes generalizado por Good (BACZKOWSKI et al., 2000). Sendo assim, apresenta-se uma nova generalização que, além de ter os índices de Shannon e Simpson como casos especiais, engloba índices mais gerais como o não familiar (PATIL & TAILIIE, 1982). Os momentos de h(a,b,d) aqui apresentados estendem os resultados apresentados em Baczkowski et al. e Bowman et al. para uma classe de índices de diversidade mais geral, concluindo-se então que enquanto a distribuição do índice de Shannon pode ser aproximado por uma distribuição Gaussiana, caso haja diferença entre abundância de espécies, para valores mais gerais de (a,b,d), sugere-se uma distribuição do tipo I como sendo a mais apropriada. Os resultados obtidos são tão consistentes quanto os de trabalhos que lidam com populações reais como em Heip & Engels (1974), principalmente quando examina-se o índice de Shannon.

Submitted by Maria Aparecida (cidazen@gmail.com) on 2017-08-18T14:02:37Z No. of bitstreams: 1 cleriston.pdf: 1605933 bytes, checksum: c1faa5f854c1a9debfbaa1affc5ab4ad (MD5) / Made available in DSpace on 2017-08-18T14:02:37Z (GMT). No. of bitstreams: 1 cleriston.pdf: 1605933 bytes, checksum: c1faa5f854c1a9debfbaa1affc5ab4ad (MD5) Previous issue date: 2009-02-12 / The diagnosis of lung nodules has been constantly looked for by researchers as a way to minimize the high global mortality indices related to lung cancer. The usage of medical images, such as Computerized Tomography, has made possible the deepening and the improvement of techniques used to evaluate exams and provide diagnosis. This work presents a methodology for diagnosing single lung nodules that can be an aid for studies performed on similar areas and for specialists. This methodology was applied to two different image databases. The representation of the nodules was done with extraction of geometry and texture features, being the last one described through Simpson’s Index, a statistic used in Spatial Analysis and in Ecology. These features were submitted to the Support Vector Machine classifier (SVM) in two approaches: the traditional approach and the approach by using One Class. With the traditional SVM approach, we have obtained sensibility rates of 90%, specificity of 96.67% and accuracy of 95%. Using One Class SVM, the obtained rates were: sensibility of 89.7%, specificity of 89.7% and accuracy of 89.7%. / O diagnóstico de nódulos pulmonares tem sido buscado constantemente por pesquisadores como forma de amenizar os altos índices de mortalidade mundial relacionado ao câncer de pulmão. O uso de imagens médicas, como a Tomografia Computadorizada, tem possibilitado um aprofundamento e melhoramento de técnicas para avaliar exames e prover diagnósticos. Este trabalho apresenta uma metodologia para diagnóstico de nódulos pulmonares solitários que possa servir como um auxílio para estudos realizados em áreas afins e para especialistas. Esta metodologia foi aplicada a duas diferentes bases de dados de imagens. A representação dos nódulos foi feita com a extração de medidas de geometria e de textura sendo esta última descrita através do Índice de Simpson, uma estatística utilizada na Análise Espacial e na Ecologia. Essas medidas foram submetidas ao classificador Máquina de Vetores de Suporte - MVS em duas abordagens: a abordagem tradicional e abordagem usando uma classe. Com abordagem MVS tradicional, obtiveramse taxas de sensibilidade de 90%, especificidade de 96,67% e acurácia de 95%. Usando MVS de uma classe, as taxas obtidas foram: sensibilidade igual a 89,7%, especificidade igual a 89,7% e acurácia igual a 89,7%.

Hastigheten för globalt utdöende är betydligt högre nu jämfört med den förmänskliga tiden, och utan åtgärder kommer utdöendet att accelerera. Detta medför ett stort ansvar på beslutsfattare som måste agera i förhållande till detta. Därför är det viktigt att kunna följa upp den biologiska mångfalden för att ta strategiska beslut, något som endast sker i begränsad skala på kommunal nivå i Sverige. Vidare finns det mycket medborgardata kring artrikedom, där frivilliga medborgare rapporterar fynd de gjort i databasen Artportalen. Möjligheten att utnyttja denna typ av data undersöks i denna fallstudie av Tierps kommun, där trenden för den biologiska mångfalden undersöktes. Därefter användes hypotesprövning för att kvantifiera osäkerheten i de resultat som framtogs. Däremot hävdar flera forskare att det finns utmaningar med att använda sådan data, därför ämnade denna studie även att undersöka dessa problem med den använda datan. Därmed togs det fram kompletterande information om plats, tid och arter för att analysera detta. Studien visade en övergripande negativ trend för den biologiska mångfalden i Tierps kommun, vilket validerades av hypotesprövningen. Gällande problemen som undersöktes kunde det konstateras att många fynd var centrerade runt särskilda platser, månader och arter, vilket begränsar möjligheten att dra säkra slutsatser gällande hela den biologiska mångfalden i kommunen. Sammanfattningsvis kunde det konstateras att de resultat som framtogs skulle behöva kompletteras av annan data alternativt av andra tillvägagångssätt. / The rate of global extinction is significantly higher today compared to the prehuman times, and without action, the extinction will accelerate. This means that there is great pressure on decision-makers to take action. It is therefore important to monitor biodiversity to make strategic decisions, something that municipalities in Sweden only do at a limited scale. At the same time, there are loads of citizen science data on species richness, where unsolicited citizens report their findings in the database Artportalen. The opportunity to utilize this type of data is explored in this case study of Tierps kommun, where the trend of biodiversity is examined. Additionally, hypothesis testing was used to quantify the uncertainty in the results. However, several scientists claim that there are challenges using such data, therefore this study also aimed to explore these. To do this, complementary information regarding time, space and species were gathered and analyzed. The results indicated that a general negative trend could be identified in biodiversity for the municipality of Tierp, which was validated with the hypothesis testing. Regarding the problems that were examined, it could be ascertained that most of the discoveries were limited to specific places, months and species, which limits the possibility to draw certain conclusions regarding the entire biodiversity in the municipality. In conclusion, it could be stated that the results that were produced need to be complemented by other data, alternatively by other methods.