Remote sensing of rice crop areas

Rice means life for millions of people and it is planted in many regions of the world. It primarily grows in the major river deltas of Asia and Southeast Asia, such as the Mekong Delta, known as the Rice Bowl of Vietnam, the second-largest rice-producing nation on Earth. However, Latin America, the USA, and Australia have extensive rice-growing regions. In addition, rice is the most rapidly growing source of food in Africa. Rice is therefore of significant importance to food security in an increasing number of low-income food-deficit countries. This review article gives a complementary overview of how remote sensing can support the assessment of paddy rice cultivation worldwide. This article presents and discusses methods for rice mapping and monitoring, differentiating between the results achievable using different sensors of various spectral characteristics and spatial resolution. The remote sensing of rice-growing areas can not only contribute to the precise mapping of rice areas and the assessment of the dynamics in rice-growing regions, but can also contribute to harvest prediction modelling, the analyses of plant diseases, the assessment of rice-based greenhouse gas (methane) emission due to vegetation submersion, the investigation of erosion-control-adapted agricultural systems, and the assessment of ecosystem services in rice-growing areas.     

Remote sensing of vegetation dynamics in West Africa

Vegetation dynamics and the lives of millions of people in West Africa are closely interlinked with each other. The high annual variability of the phenological cycle considerably affects the agricultural population with late rainfalls and droughts, often resulting in serious food crises. On the other hand, the rapidly growing population has a great need for space due to expanding cities and a low agricultural efficiency. This situation, together with a changing climate, has had a strong impact on vegetation dynamics in West Africa and will play a major role in the future. The dynamic nature of vegetation in the region has attracted a lot of remote-sensing-based research in the past 30 years and has lead to heated discussions. This review article gives a comprehensive overview of the studies on remotely sensed vegetation dynamics in West Africa. After an introduction to the specific situation for vegetation dynamics in West Africa, the applied sensors and their suitability for the region are outlined. Research on the assessment of different plant parameters, on phenological metrics as well as on the monitoring of agricultural areas is outlined and discussed. Furthermore, a major part of this review is dedicated to the analyses undertaken to assess vegetation trends in West Africa over the past 30 years and their potential human and climatic causes. Finally, identified research gaps and challenges for future studies are discussed.     

A Framework for the Analysis of Governance Structures Applying to Groundwater Resources and the Requirements for the Sustainable Management of Associated Ecosystem Services

The competing demands placed on groundwater for socio-economic and for ecological benefits, and the resultant tradeoffs, represent a major challenge for the management arena. The governance of groundwater resources and the sustainable management of associated ecosystem services must take into consideration human and biophysical characteristics as intertwined systems. Frameworks and analytical tools are required to help understand complex governance regimes, and the linkages between management and the corresponding effects on ecosystem services. Presented in this paper is a framework for the analysis of groundwater governance based on the adaptive management approach and the ecosystem services concept. Governance can be analyzed on the basis of certain characteristics. One characteristic of a governance regime assumed to be crucial for adaptive and sustainable management is vertical integration, which refers to the connectedness of different administrative levels, including the involvement of non-governmental stakeholders in decision-making and planning processes. The framework was applied in the Upper Guadiana Basin in Spain, where the intensive use of groundwater has led to significant conflicts between farmers, authorities and environmental conservation groups. The analysis showed that conflicts arose from a lack of vertical integration; e.g., one-way communication between official authorities and the exclusion of local stakeholders during planning processes. The framework is deemed to be a strong analytical tool as it provides a basis for organized and context-specific case study assessment and renders complex groundwater management more transparent and comprehensible. The framework will be further applied and enhanced for application in international case studies.     

Identifying duplicate functionality in textual use cases by aligning semantic actions

Developing high-quality requirements specifications often demands a thoughtful analysis and an adequate level of expertise from analysts. Although requirements modeling techniques provide mechanisms for abstraction and clarity, fostering the reuse of shared functionality (e.g., via UML relationships for use cases), they are seldom employed in practice. A particular quality problem of textual requirements, such as use cases, is that of having duplicate pieces of functionality scattered across the specifications. Duplicate functionality can sometimes improve readability for end users, but hinders development-related tasks such as effort estimation, feature prioritization, and maintenance, among others. Unfortunately, inspecting textual requirements by hand in order to deal with redundant functionality can be an arduous, time-consuming, and error-prone activity for analysts. In this context, we introduce a novel approach called ReqAligner that aids analysts to spot signs of duplication in use cases in an automated fashion. To do so, ReqAligner combines several text processing techniques, such as a use case-aware classifier and a customized algorithm for sequence alignment. Essentially, the classifier converts the use cases into an abstract representation that consists of sequences of semantic actions, and then these sequences are compared pairwise in order to identify action matches, which become possible duplications. We have applied our technique to five real-world specifications, achieving promising results and identifying many sources of duplication in the use cases.     

A versatile hardware architecture for a constant false alarm rate processor based on a linear insertion sorter

Constant False Alarm Rate (CFAR) algorithms are used in digital signal processing applications to extract targets from background in noisy environments. Some examples of applications are target detection in radar environments, image processing, medical engineering, power quality analysis, features detection in satellite images, Pseudo-Noise (PN) code detectors, among others. This paper presents a versatile hardware architecture that implements six variants of the CFAR algorithm based on linear and nonlinear operations for radar applications. Since some implemented CFAR algorithms require sorting the input samples, a linear sorter based on a First In First Out (FIFO) schema is used. The proposed architecture, known as CFAR processor, can be used as a specialized module or co-processor for Software Defined Radar (SDR) applications. The results of implementing the CFAR processor on a Field Programmable Gate Array (FPGA) are presented and discussed.     

Medical data mining: insights from winning two competitions

Two major data mining competitions in 2008 presented challenges in medical domains: KDD Cup 2008, which concerned cancer detection from mammography data; and Informs Data Mining Challenge 2008, dealing with diagnosis of pneumonia based on patient information from hospital files. Our team won both of these competitions, and in this paper we share our lessons learned and insights. We emphasize the aspects that pertain to the general practice and methodology of medical data mining, rather than to the specifics of each modeling competition. We concentrate on three topics: information leakage, its effect on competitions and proof-of-concept projects; consideration of real-life model performance measures in model construction and evaluation; and relational learning approaches to medical data mining tasks.     

Topological Engineering of Pt-Group-Metal-Based Chiral Crystals toward High-Efficiency Hydrogen Evolution Catalysts

It has been demonstrated that topological nontrivial surface states can favor heterogeneous catalysis processes such as the hydrogen evolution reaction (HER), but a further decrease in mass loading and an increase in activity are still highly challenging. The observation of massless chiral fermions associated with large topological charge and long Fermi arc (FA) surface states inspires the investigation of their relationship with the charge transfer and adsorption process in the HER. In this study, it is found that the HER efficiency of Pt-group metals can be boosted significantly by introducing topological order. A giant nontrivial topological energy window and a long topological surface FA are expected at the surface when forming chiral crystals in the space group of P2₁3 (#198). This makes the nontrivial topological features resistant to a large change in the applied overpotential. As HER catalysts, PtAl and PtGa chiral crystals show turnover frequencies as high as 5.6 and 17.1 s⁻¹ and an overpotential as low as 14 and 13.3 mV at a current density of 10 mA cm⁻². These crystals outperform those of commercial Pt and nanostructured catalysts. This work opens a new avenue for the development of high-efficiency catalysts with the strategy of topological engineering of excellent transitional catalytic materials.     

Comparison of Gas and Liquid Propylene Polymerization Technique – Hydrogen Effect on Thermal,Rheological, and Morphological Properties of PP

Summary: A comparison of PP qualities, which are produced with two different polymerization techniques–gas phase(GP) and liquid pool (LP)–under precise control of the polymerization temperature (70 °C) and pressure (GP = 25 bar, LP < 60 bar) using identical Ziegler‐Natta catalyst (TiCl₄/phthalate/MgCl₂ + TEA/silane), is presented. A series of homopolymer PP in a wide MW range from 100 000 to 1 600 000 g · mol^?1 was polymerized. During polymerization all samples were characterized exactly by their Rp‐profil. The effect of hydrogen on the initial reaction rate and on MW and MWD was analyzed on the basis of this so‐called kinetic fingerprint. The results showed that the polymerization rate reached a maximum for LP, of about 150 kg · g_cat^?1 · h^?1, in contrast to GP with a maximum of R_p,₀ = 45 kg · g_cat^?1 · h^?1. Analysis was carried out by means of GPC, SEM, DSC, platte‐platte rheometer, and WAXS. The results first showed that the MWD of LP PP is narrower (PD ～ 6.8) than for the GP PP (PD ～ 8), polymerized in two steps. An SEM study of the powder particle shows the typical dent surface morphology of polymers using Ziegler‐Natta catalysts for polymerization. WAXS and DSC analysis demonstrated that almost only the α‐modification of crystalline structure exists and that the crystallinity becomes considerably higher after solidification from melt. Furthermore, it was found that the crystallite size distribution depends on the polymerization technique. Rheological studies indicate that GP PP behaves more elastically. To summarize, it is shown that PP produced with the LP polymerization technique is more homogenous and of high quality.

Particle geometry of gas phase and liquid pool polymerized PP powder observed by SEM (PP‐L0).     

Forensic studies of a large cover‐plate steel moment‐resisting connection

A large‐size, single‐sided cover plate connection composed of a built‐up BW36×670 column and a W36×359 rolled beam section was tested in a custom‐made test fixture using the SAC Phase I loading protocol. A trapezoidal plate was used as top flange reinforcement and a rectangular plate was used as bottom flange reinforcement. The test specimen failed catastrophically at a story drift angle of 1.7% and a beam plastic rotation of 0.009 radian by fracture through the beam top flange and beam web. An ABAQUS nonlinear finite element model of the connection was prepared and analyzed. The ABAQUS data indicate that the likelihood of brittle or ductile fracture at the observed crack initiation site is very low. Fractographic and microstructure studies were conducted after testing. The fractographic analysis of the failure surface showed that the fracture initiated at the toe of a fillet weld that joined the top cover plate to the beam flange. The microstructure analysis around the crack initiation site revealed laminations in the base metal at the crack initiation site. Copyright © 2002 John Wiley & Sons, Ltd.     

The promotion of women's cooperatives in Mexico: Is feminist technical assistance an Oxymoron?

This article examines one of the fundamental dilemmas in grass roots planning practice—how to provide planning expertise to disenfranchised clients while not creating systems of dependence among those clients on that expertise. Specifically, the article investigates attempts to provide feminist technical assistance to women in rural production cooperatives in three communities in central Mexico. The three cases provide both positive and negative insights into how to provide empowering, and feminist, technical assistance. The cases raise questions about two issues in local development planning for women: why is it that a ‘cult of expertise’ tends to develop in technical assistance agencies, and how can we develop alternative approaches that respect women's ‘local knowledge'?; and how can cooperatives construct a feminist labour process’ that integrates domestic and market relations.