One of the main problems in urban and environmental management concerns the unavailability of reliable spatial data in a spatial data infrastructure (SDI) environment. The main reason for the problem ...of spatial data availability is the time-consuming nature of their manual production. The present paper proposes the development of on-demand data production Web services for the Internet using feature extraction techniques from satellite images as a solution to the problem. Such services allow users to connect to an on-demand data production Web service to produce the required data automatically if the users cannot find the required spatial data. In order to address and investigate this suggestion, a prototype system is developed. We have developed and implemented a system for automatic road extraction and describe it in special detail with a case study. Web service technologies and OGC (open geospatial consortium) frameworks are utilized for the development of the system to satisfy data and access interoperability in a SDI environment. The paper explains that the on-demand feature extraction Web service can facilitate the development of SDI by resolving the problem of spatial data availability. It also describes further research and different topics that should be considered in the development of SDIs to make such Web services operational.
Spatial data and related technologies have proven to be crucial for effective collaborative decision-making in disaster management. However, there are currently substantial problems with ...availability, access and usage of reliable, up-to-date and accurate data for disaster management. This is a very important aspect to disaster response as timely, up-to-date and accurate spatial data describing the current situation is paramount to successfully responding to an emergency. This includes information about available resources, access to roads and damaged areas, required resources and required disaster response operations that should be available and accessible for use in a short period of time. Any problem or delay in data collection, access, usage and dissemination has negative impacts on the quality of decision-making and hence the quality of disaster response. Therefore, it is necessary to utilize appropriate frameworks and technologies to resolve current spatial data problems for disaster management.
This paper aims to address the role of Spatial Data Infrastructure (SDI) as a framework for the development of a web-based system as a tool for facilitating disaster management by resolving current problems with spatial data. It is argued that the design and implementation of an SDI model and consideration of SDI development factors and issues, together with development of a web-based GIS, can assist disaster management agencies to improve the quality of their decision-making and increase efficiency and effectiveness in all levels of disaster management activities.
The paper is based on an ongoing research project on the development of an SDI conceptual model and a prototype web-based system which can facilitate sharing, access and usage of spatial data in disaster management, particularly disaster response.
The aim of road detection is to discriminate between road and background pixels. This discrimination is considered to be the most important stage in automatic road network extraction from satellite ...imagery. In this paper, neural networks are applied to high-resolution IKONOS and QuickBird images for road detection. This paper has endeavored to optimize the functionality of neural networks using a variety of texture parameters. These parameters had different window sizes and gray level numbers, not only from the source but also from the preclassified image. It was discovered that using texture parameters from a preclassified image accompanied by primary spectral information in reclassifying the source image could improve both road and background detection ability of the neural network. Accuracy assessment parameters were evaluated on several pan-sharpened IKONOS and QuickBird images. The obtained results attest to the efficiency of the proposed method.
In this paper pixel-based and object-oriented classifications were investigated for land-cover mapping in an urban area. Since the image fusion methods are playing a useful role in supplying ...classification different fusion approaches such as Gram-Schmidt Transform (GS), Principal Component Transform (PC), Haar wavelet, and À Trous Wavelet Transform (ATWT) algorithms have been used and the fused image with the best quality has been assessed on its respected classification. A Hyperion image and IRS-PAN image covering a region near Tehran, Iran have been used to demonstrate the enhancement and accuracy assessment of fused image over the initial images. The evaluation results of fused images showed that the Haar wavelet approach has good quality in preserving spectral information as well as spatial information. Classification results were compared to evaluate the effectiveness of the two classification approaches. Result of the pan-sharpened image classifications displayed that the object-oriented procedure presented more accurate outcomes (90.47 %) than those obtained by pixel-based classification method (77.33 %).
This study has been carried out with the objective of isolation and identification of agent(s) of pasteurella pneumonia in sheep and goat in Iran using bacteriological and biochemical assays to be ...identified in the pursuant researches to be used in pasteurellosis vaccine production. To accomplish this objective, samples were gathered from areas suspicious to pasteurellosis infection and industrial abbatoirs according to clinical and autopsy symptoms from eight provinces of Bushehr, Esfahan, Kerman, Kohgilooyeh & Boyr Ahmad, Fars, Qom, Tehran and Qazvin in a period from spring 2008 to spring 2011. Samples were different in sort due to the existent condition but generally were comprised of palatine tonsil swabs or blood samples taken from jugular vein in live animals and lungs or upper respiratory tract lymph glands in dead or slaughtered animals. Totally, 1454 samples (1120 samples of sheep, 334 samples of goat composed if 1084 samples of live animals and 370 samples of dead or slaughterd animals) were tested. Considering results obtained from assays, only 54 samples (3.71%) were assessed as being pasteurella, genus of which was totally identified as multocida.
A new glacier inventory of Iran Moussavi, M.S.; Zoej, M.J. Valadan; Vaziri, F. ...
Annals of glaciology,
2009, Letnik:
50, Številka:
53
Journal Article
Recenzirano
Odprti dostop
A new glacier inventory of Iran, compiled according to GLIMS guidelines through the use of photogrammetry and remote sensing supported by fieldwork, provides the first comprehensive study of its ...mountain glaciers. The glaciers are found in five main areas: two in the higher elevations of the Alborz mountain range (Damavand and Takhte–Soleiman regions), two on the Zardkuh and Oshtorankuh mountain chain in the Zagros mountain range and one in the Sabalan Mountains in northwest Iran. Several important glacier attributes, including minimum and maximum height of ice, area and maximum length and width, together with glacier extent, were successfully extracted using aerial and satellite imagery. Thereafter a comprehensive glacier database was established in a GIS environment.
Graphical demonstration of influence of ambient pressure (vacuum and air) and pulse repetition rate (0.01 to 200 kHz) on surface structures generated by femtosecond laser irradiation.
Display omitted
...•Laser surface structuring of silicon for varying repetition rate and ambient.•Threshold fluence and surface morphology changes with ambient pressure.•Laser-target energy coupling reduces at higher pulse repetition rates.•Ripples period is independent of the repetition rate but influenced by the ambient.•In air, the plume shielding becomes significant at repetition rates >10 kHz.
The process of surface structuring of a silicon target with femtosecond laser pulses (pulse width ≈180 fs; wavelength λ≈1030 nm) at repetition rates varying from 0.01 to 200 kHz is investigated in vacuum and in air, in static irradiation conditions. The threshold fluence for the formation of a shallow crater, as well as the surface features generated inside the crater, are analyzed at different repetition rate for a fixed sequence of N laser pulses. Our experimental results evidence a clear difference in the morphology of the surface structures generated in vacuum and air, addressing a change in the laser-target energy coupling at the higher pulse repetition rates. The observed behavior is rationalized in terms of the effects induced by the presence of nanoparticle debris, as well as of a plume shielding occurring at repetition rates larger than 10 kHz in air. Both such effects are hindered for vacuum irradiation conditions. Our experimental findings highlight the impact of plume shielding, and nanoparticles coverage on laser material processing in air at high repetition rates. These observations, thus, provide new useful insights in the field of fast laser processing essentially required in many applications of nanoscience and nanotechnologies.
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