Literature survey

About: Literature survey is a research topic. Over the lifetime, 15372 publications have been published within this topic receiving 459196 citations.

Global flood depth-damage functions: Methodology and the database with guidelines

Abstract: Assessing potential damage of flood events is an important component in flood risk management. Determining direct flood damage is commonly done using depth-damage curves, which denote the flood damage that would occur at specific water depths per asset or per land-use class. Many countries have developed flood damage models using depth-damage curves based on analysis of past flood events and on expert judgement. However, the fact that such damage curves are not available for all regions hampers damage assessments in some areas. Moreover, due to different methodologies employed for various damage models in different countries, damage assessments cannot be directly compared with each other, obstructing also supra-national flood damage assessments. To address these problems a globally consistent database of depth-damage curves has been developed. This dataset contains damage curves depicting fractional damage as a function of water depth as well as the relevant maximum damage values for a variety of assets and land use classes. Based on an extensive literature survey normalised damage curves have been developed for each continent, while differentiation in flood damage between countries is established by determining maximum damage values at the country scale. These maximum damage values are based on construction cost surveys from multinational construction companies, which provide a coherent set of detailed building cost data across dozens of countries. A consistent set of maximum flood damage values for all countries was computed using statistical regressions with socio-economic World Development Indicators. Further, based on insights from the literature survey, guidance is also given on how the damage curves and maximum damage values can be adjusted for specific local circumstances, such as urban vs. rural locations or use of specific building material. This dataset can be used for consistent supra-national scale flood damage assessments, and guide assessment in countries where no damage model is currently available.

The state of African cattle genetic resources I. Classification framework and identification of threatened and extinct breeds

Abstract: Summary A field and literature survey was conducted to determine the status of cattle genetic resources of sub-Saharan Africa and to identify cattle breeds at risk and those which may have become extinct over the last century. This paper - in two parts - summarises preliminary results of the survey. The survey revealed that sub-Saharan Africa is home to a total of 145†cattle breeds/strains comprising two taurine Longhorns, 15 taurine Shorthorns, 75†zebu (Bos indicus), 30 sanga, eight zenga (zebu-sanga), nine breeds derived from interbreeding of indigenous breeds/strains located in close proximity to each other, and six systematically created composite breeds. Out of the 145 breeds identified from the survey, 47 (about 32%) were considered to be at risk of extinction. Risk categories used were: Critical (most severe), Endangered, Vulnerable, and Rare (least severe). Of the breeds identified to be at risk of extinction, six were in the iRarei category, 10 were iVulnerablei, another 10 were iEndangeredi and 15 were in the iCriticali category. A total of 22 breeds (about 13%) previously recognised in the continent have become extinct in the last century. This number excludes some populations which have lost their individual identity due to admixtures involving two or more originally distinct breeds.

Selective ensembles in supported palladium sulfide nanoparticles for alkyne semi-hydrogenation.

Abstract: Ensemble control has been intensively pursued for decades to identify sustainable alternatives to the Lindlar catalyst (PdPb/CaCO3) applied for the partial hydrogenation of alkynes in industrial organic synthesis. Although the geometric and electronic requirements are known, a literature survey illustrates the difficulty of transferring this knowledge into an efficient and robust catalyst. Here, we report a simple treatment of palladium nanoparticles supported on graphitic carbon nitride with aqueous sodium sulfide, which directs the formation of a nanostructured Pd3S phase with controlled crystallographic orientation, exhibiting unparalleled performance in the semi-hydrogenation of alkynes in the liquid phase. The exceptional behavior is linked to the multifunctional role of sulfur. Apart from defining a structure integrating spatially-isolated palladium trimers, the active ensembles, the modifier imparts a bifunctional mechanism and weak binding of the organic intermediates. Similar metal trimers are also identified in Pd4S, evidencing the pervasiveness of these selective ensembles in supported palladium sulfides.

A survey of resilience differentiation frameworks in communication networks

Abstract: Unintentional failures affect links and nodes in communication networks. Recovery mechanisms are the key tool for achieving the dependability required by the services using the network. However, high dependability in communication networks comes at a high cost in terms of the capacity needed by these mechanisms.The traffic from all services and users is carried by the same backbone network. Since the users and services have different requirements, and users have different willingness to pay for a high quality of service, it is desirable to have methods that enable provision of different levels of dependability in the same network, i.e. dependability differentiation. The thesis addresses dependability differentiation in connection-oriented backbone communication networks. Two methods to provide connections meeting differentiated guarantees on the asymptotic availability are proposed.The first of these uses a novel flexible arrangement for dedicated protection denoted a protection pattern. The protection pattern is used in a proposed distributed connection management system. The system is compared with alternative proposals based on centralized management and shows good performance. The second proposal uses shared protection, which may potentially use less resources in terms of bandwidth, but has higher complexity than dedicated protection. The proposed system is based on rules to control the sharing to enable provision of guarantees. Simulation results show that the proposed method performs significantly better than an alternative strategy based on dedicated protection.A different approach to availability-guaranteed services is to offer guarantees on the interval availability which is a measure commonly used Service Level Agreements (SLAs). The thesis contains a proposal of using adaptive management to increase compliance with interval availability guarantees. Different adaptive management policies are proposed and compared to alternative static provisioning policies in a case study. The thesis also addresses the problem of measuring dependability by simulation. To reduce the simulation effort needed to obtain precise estimates of dependability attributes, a rare-event simulation technique has been applied to the well-known Network Simulator 2 (NS2). The results show that the technique is applicable to this types of simulation scenario, but the gain is modest. The thesis also contains a broad literature survey of dependability differentiation research. This is the first survey of the topic. Hence, it is in itself a significant contribution. A classification scheme for how to approach differentiation is proposed and a critical evaluation of the state of art is given.This thesis contributes to fill in some of the ``gaps'' identified, but there are still significant challenges ahead before differentiation may be deployed in operational networks.

Public procurement and corruption in Bangladesh confronting the challenges and opportunities

Abstract: In new democracies like Bangladesh code of conduct, the ethics and issues of conflict of interest have not been accorded a high priority for legislative and administrative reforms. To discuss the role of public administration in Bangladesh and recommends measures to be adopted to prevent corruption in public procurement. Information on global and regional in connection to procurement and corruption were retrieved from documents available mainly on electronic databases, literature survey, on websites of specialized agencies and analysis of the existing situation in Bangladesh held. In Bangladesh contract awards provide opportunities for procurement. There are reports of wide-ranging corruption, political control and pressure from trade unions in the procurement process. Public trust in the process is generally absent. The World Banks evaluation of Bangladesh concluded that the implementation of procurement process is far from satisfactory, due to the following problems, poor advertisement, short bidding periods, poor specifications, nondisclosure of selection criteria, contract awards by lottery, one-sided contract documents, negotiations with all bidders and rebidding without adequate grounds, occurrence of corruption involving donor agency are not uncommon at nationally or globally and or other levels. The interesting finding is that procurement happens to be one of the lucrative areas, where corruption of above nature, therefore, the quality of public administration must be improved and accountable, which is an integral part of good governance. Key words: Procurement, corruption, e-procurement, public policy and administration,