4,413 research outputs found
Destination directed packet switch architecture for a 30/20 GHz FDMA/TDM geostationary communication satellite network
Emphasis is on a destination directed packet switching architecture for a 30/20 GHz frequency division multiplex access/time division multiplex (FDMA/TDM) geostationary satellite communication network. Critical subsystems and problem areas are identified and addressed. Efforts have concentrated heavily on the space segment; however, the ground segment was considered concurrently to ensure cost efficiency and realistic operational constraints
On"good"politicians and"bad"policies - social cohesion, institutions, and growth
Social cohesion - that is, the inclusiveness of a country's communities - is essential for generating the trust needed to implement reforms. Citizens have to trust that the short-term losses that inevitably arise from reform, will be more than offset by long-term gains. However, in countries divided along class and ethnic lines, and with weak institutions, even the boldest, most civic-minded and well-informed politician (or interest group) will face severe constraints in bringing about policy reform. The authors hypothesize that key development outcomes (particularly economic growth) are most likely to be associated with countries that are both socially cohesive and governed by effective public institutions. They test this hypothesis for the sample of countries with available data. The authors develop a conceptual framework based on the idea of social cohesion, then review the evidence on which it is based. While several earlier studies have shown that differences in growth rates among developing countries are a result of weak rule of law, lack of democracy, and other institutional deficiencies, the authors focus on the social conditions that give rise to these deficiencies. They also seek to establish empirically a causal sequence from social divisions to weak institutions to slow growth. The essence of their argument, supported by new econometric evidence, is that pro-development policies are comparatively rare in the developing world less because of the moral fiber of politicians (though that surely matters) than because good politicians typically lack the room for maneuver needed to make desired reforms. This lack of maneuverability is a product of insufficient social cohesion and weak institutions. The authors also explore the determinants of social cohesion, focusing on historical accidents, initial conditions, and natural resource endowments. Social cohesion should not be seen as a concern primarily of developing and transition economies. Indeed, it is important in the United Kingdom as in Ukraine, in Canada as in Colombia, in the Netherlands as in Australia.Social Capital,Decentralization,Labor Policies,Public Health Promotion,Community Development and Empowerment,Inequality,Poverty Assessment,Economic Development,Governance Indicators,Social Capital
Destination-directed, packet-switching architecture for 30/20-GHz FDMA/TDM geostationary communications satellite network
A destination-directed packet switching architecture for a 30/20-GHz frequency division multiple access/time division multiplexed (FDMA/TDM) geostationary satellite communications network is discussed. Critical subsystems and problem areas are identified and addressed. Efforts have concentrated heavily on the space segment; however, the ground segment has been considered concurrently to ensure cost efficiency and realistic operational constraints
The active microbial community more accurately reflects the anaerobic digestion process: 16S rRNA (gene) sequencing as a predictive tool
Background:
Amplicon sequencing methods targeting the 16S rRNA gene have been used extensively to investigate microbial community composition and dynamics in anaerobic digestion. These methods successfully characterize amplicons but do not distinguish micro-organisms that are actually responsible for the process. In this research, the archaeal and bacterial community of 48 full-scale anaerobic digestion plants were evaluated on DNA (total community) and RNA (active community) level via 16S rRNA (gene) amplicon sequencing.
Results:
A significantly higher diversity on DNA compared with the RNA level was observed for archaea, but not for bacteria. Beta diversity analysis showed a significant difference in community composition between the DNA and RNA of both bacteria and archaea. This related with 25.5 and 42.3% of total OTUs for bacteria and archaea, respectively, that showed a significant difference in their DNA and RNA profiles. Similar operational parameters affected the bacterial and archaeal community, yet the differentiating effect between DNA and RNA was much stronger for archaea. Co-occurrence networks and functional prediction profiling confirmed the clear differentiation between DNA and RNA profiles.
Conclusions:
In conclusion, a clear difference in active (RNA) and total (DNA) community profiles was observed, implying the need for a combined approach to estimate community stability in anaerobic digestion
Analysis of the Republic of Korea Food Grain Situation
Two problems for developing economies confronted with food shortages are (1) how to acquire sufficient food and still stabilize food prices in the short-run and (2) how to increase food production and realize food self-sufficiency in the long-run. Solving these two problems is often considered a precondition to achieving steady economic growth and industrialization. This study was concerned with the Republic of Korea, where economic development plans have been initiated during the last two decades under the condition of annual food grain shortages. Efforts to overcome these shortages have resulted in South Korea becoming the fastest growing major market for U.S. farm products in the Far East. The main purpose of this study was to analyze the relationships between government food grain policy and the consumption and supply of food grains. Food grains under analysis were limited to rice, barley and wheat (major food grains) which are the main dietary items in Korea
The mosaic test:benchmarking colour-based image retrieval systems using image mosaics
Evaluation and benchmarking in content-based image retrieval has always been a somewhat neglected research area, making it difficult to judge the efficacy of many presented approaches. In this paper we investigate the issue of benchmarking for colour-based image retrieval systems, which enable users to retrieve images from a database based on lowlevel colour content alone. We argue that current image retrieval evaluation methods are not suited to benchmarking colour-based image retrieval systems, due in main to not allowing users to reflect upon the suitability of retrieved images within the context of a creative project and their reliance on highly subjective ground-truths. As a solution to these issues, the research presented here introduces the Mosaic Test for evaluating colour-based image retrieval systems, in which test-users are asked to create an image mosaic of a predetermined target image, using the colour-based image retrieval system that is being evaluated. We report on our findings from a user study which suggests that the Mosaic Test overcomes the major drawbacks associated with existing image retrieval evaluation methods, by enabling users to reflect upon image selections and automatically measuring image relevance in a way that correlates with the perception of many human assessors. We therefore propose that the Mosaic Test be adopted as a standardised benchmark for evaluating and comparing colour-based image retrieval systems
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