21,927 research outputs found
Huddl: the Hydrographic Universal Data Description Language
Since many of the attempts to introduce a universal hydrographic data format have failed or have been only partially successful, a different approach is proposed. Our solution is the Hydrographic Universal Data Description Language (HUDDL), a descriptive XML-based language that permits the creation of a standardized description of (past, present, and future) data formats, and allows for applications like HUDDLER, a compiler that automatically creates drivers for data access and manipulation. HUDDL also represents a powerful solution for archiving data along with their structural description, as well as for cataloguing existing format specifications and their version control. HUDDL is intended to be an open, community-led initiative to simplify the issues involved in hydrographic data access
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Normative, systemic and procedural aspects: a review of indicatorâbased sustainability assessments in agriculture
Several methods for assessing the sustainability of agricultural systems have been developed. These methods do not fully: (i) take into account the multiâfunctionality of agriculture; (ii) include multidimensionality; (iii) utilize and implement the assessment knowledge; and (iv) identify conflicting goals and tradeâoffs. This paper reviews seven recently developed multidisciplinary indicatorâbased assessment methods with respect to their contribution to these shortcomings. All approaches include (1) normative aspects such as goal setting, (2) systemic aspects such as a specification of scale of analysis, (3) a reproducible structure of the approach. The approaches can be categorized into three typologies. The topâdown farm assessments focus on field or farm assessment. They have a clear procedure for measuring the indicators and assessing the sustainability of the system, which allows for benchmarking across farms. The degree of participation is low, potentially affecting the implementation of the results negatively. The topâdown regional assessment assesses the onâfarm and the regional effects. They include some participation to increase acceptance of the results. However, they miss the analysis of potential tradeâoffs. The bottomâup, integrated participatory or transdisciplinary approaches focus on a regional scale. Stakeholders are included throughout the whole process assuring the acceptance of the results and increasing the probability of implementation of developed measures. As they include the interaction between the indicators in their system representation, they allow for performing a tradeâoff analysis. The bottomâup, integrated participatory or transdisciplinary approaches seem to better overcome the four shortcomings mentioned above
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Why donât pesticide applicators protect themselves? Exploring the use of personal protective equipment among Colombian smallholders
The misuse of personal protective equipment (PPE)
during pesticide application was investigated among
smallholders in Colombia. The integrative agent-centered
(IAC) framework and a logistic regression
approach were adopted. The results suggest that the
descriptive social norm was significantly influencing
PPE use. The following were also important: (1) having
experienced pesticide-related health problems; (2)
age; (3) the share of pesticide application carried out;
and (4) the perception of PPE hindering work. Interestingly,
the influence of these factors differed for different
pieces of PPE. Since conformity to the social
norm is a source of rigidity in the system, behavioral
change may take the form of a discontinuous transition.
In conclusion, five suggestions for triggering a
transition towards more sustainable PPE use are formulated:
(1) diversifying targets/tools; (2) addressing
structural aspects; (3) sustaining interventions in the
long-term; (4) targeting farmersâ learning-by-experience;
and (5) targeting PPE use on a collective level
HUDDL for description and archive of hydrographic binary data
Many of the attempts to introduce a universal hydrographic binary data format have failed or have been only partially successful. In essence, this is because such formats either have to simplify the data to such an extent that they only support the lowest common subset of all the formats covered, or they attempt to be a superset of all formats and quickly become cumbersome. Neither choice works well in practice. This paper presents a different approach: a standardized description of (past, present, and future) data formats using the Hydrographic Universal Data Description Language (HUDDL), a descriptive language implemented using the Extensible Markup Language (XML). That is, XML is used to provide a structural and physical description of a data format, rather than the content of a particular file. Done correctly, this opens the possibility of automatically generating both multi-language data parsers and documentation for format specification based on their HUDDL descriptions, as well as providing easy version control of them. This solution also provides a powerful approach for archiving a structural description of data along with the data, so that binary data will be easy to access in the future. Intending to provide a relatively low-effort solution to index the wide range of existing formats, we suggest the creation of a catalogue of format descriptions, each of them capturing the logical and physical specifications for a given data format (with its subsequent upgrades). A C/C++ parser code generator is used as an example prototype of one of the possible advantages of the adoption of such a hydrographic data format catalogue
Development of a fusion adaptive algorithm for marine debris detection within the post-Sandy restoration framework
Recognition of marine debris represent a difficult task due to the extreme variability of the marine environment, the possible targets, and the variable skill levels of human operators. The range of potential targets is much wider than similar fields of research such as mine hunting, localization of unexploded ordnance or pipeline detection. In order to address this additional complexity, an adaptive algorithm is being developing that appropriately responds to changes in the environment, and context.
The preliminary step is to properly geometrically and radiometrically correct the collected data. Then, the core engine manages the fusion of a set of statistically- and physically-based algorithms, working at different levels (swath, beam, snippet, and pixel) and using both predictive modeling (that is, a high-frequency acoustic backscatter model) and phenomenological (e.g., digital image processing techniques) approaches. The expected outcome is the reduction of inter-algorithmic cross-correlation and, thus, the probability of false alarm. At this early stage, we provide a proof of concept showing outcomes from algorithms that dynamically adapt themselves to the depth and average backscatter level met in the surveyed environment, targeting marine debris (modeled as objects of about 1-m size).
The project relies on a modular software library, called Matador (Marine Target Detection and Object Recognition)
Coupled Lugiato-Lefever equation for nonlinear frequency comb generation at an avoided crossing of a microresonator
Guided-mode coupling in a microresonator generally manifests itself through
avoided crossings of the corresponding resonances. This coupling can strongly
modify the resonator local effective dispersion by creating two branches that
have dispersions of opposite sign in spectral regions that would otherwise be
characterized by either positive (normal) or negative (anomalous) dispersion.
In this paper, we study, both analytically and computationally, the general
properties of nonlinear frequency comb generation at an avoided crossing using
the coupled Lugiato-Lefever equation. In particular, we find that bright
solitons and broadband frequency combs can be excited when both branches are
pumped for a suitable choice of the pump powers and the detuning parameters. A
deterministic path for soliton generation is found.Comment: 9 pages, 5 figure
Efficient mining of discriminative molecular fragments
Frequent pattern discovery in structured data is receiving
an increasing attention in many application areas of sciences. However, the computational complexity and the large amount of data to be explored often make the sequential algorithms unsuitable. In this context high performance distributed computing becomes a very interesting and promising approach. In this paper we present a parallel formulation of the frequent subgraph mining problem to discover interesting patterns in molecular compounds. The application is characterized by a highly irregular tree-structured computation. No estimation is available for task workloads, which show a power-law distribution in a wide range. The proposed approach allows dynamic resource aggregation and provides fault and latency tolerance. These features make the distributed application suitable for multi-domain heterogeneous environments, such as computational Grids. The distributed application has been evaluated on the well known National Cancer Instituteâs HIV-screening dataset
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