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Mokarram M.,Shiraz University | Sathyamoorthy D.,Malaysian Science and Technology Research Institute for Defence
IOP Conference Series: Earth and Environmental Science | Year: 2016

The aim of this study is to cluster landforms in the west of the Fars province, Iran using self-organizing maps (SOM). In SOM, according to qualitative data, the clustering tendencies of landforms were investigated using six morphometric parameters, which were slope, profile, plan, elevation, curvature and aspect. First, topographic position index (TPI) was used to prepare the landform classification map. The results of SOM showed that there were five classes for landform classification in the study area. Cluster 5 corresponds to high slope, high elevation but with different of concavity and convexity that consist of ridge landforms. Cluster 3 corresponds to flat areas, possibly plantation areas, in medium elevation and almost flat terrain. Clusters 1, 2 and 4 correspond to channels with different slope conditions.


Mokarram M.,Shiraz University | Sathyamoorthy D.,Malaysian Science and Technology Research Institute for Defence
Solid Earth | Year: 2016

Soil genesis is highly dependent on landforms as they control the erosional processes and the soil physical and chemical properties. The relationship between landform classification and electrical conductivity (EC) of soil and water in the northern part of Meharloo watershed, Fars province, Iran, was investigated using a combination of a geographical information system (GIS) and a fuzzy model. The results of the fuzzy method for water EC showed 36.6% of the land to be moderately land suitable for agriculture; high, 31.69 %; and very high, 31.65 %. In comparison, the results of the fuzzy method for soil EC showed 24.31% of the land to be as not suitable for agriculture (low class); moderate, 11.78 %; high, 25.74 %; and very high, 38.16 %. In total, the land suitable for agriculture with low EC is located in the north and northeast of the study area. The relationship between landform and EC shows that EC of water is high for the valley classes, while the EC of soil is high in the upland drainage class. In addition, the lowest EC levels for soil and water are in the plains class. © Author(s) 2016.


Mohamad Hani A.F.,Petronas University of Technology | Sathyamoorthy D.,Malaysian Science and Technology Research Institute for Defence | Sagayan Asirvadam V.,Petronas University of Technology
Computers and Geosciences | Year: 2012

In this paper, a modification of the algorithm proposed by Ahmad Fadzil et al. (2011) for surface roughness computation from digital elevation models (DEMs) via multiscale analysis is presented. The new algorithm takes into account that the three predominant physiographic features of terrains (mountains, basins and piedmont slopes) have distinct curvature region distributions and hence, distinct roughness characteristics. To this end, the surface roughness of individual cells of DEMs is computed by identifying the curvature region distribution and roughness characteristics of each individual mountain, basin and piedmont slope region. The modified algorithm allows for the localisation and quantification curvature regions over varying scales for specific regions, providing a more appropriate surface roughness parameter. © 2011 Elsevier Ltd.


Hani A.F.M.,Petronas University of Technology | Sathyamoorthy D.,Malaysian Science and Technology Research Institute for Defence | Sagayan Asirvadam V.,Petronas University of Technology
Computers and Geosciences | Year: 2011

In this paper, an algorithm to compute surface roughness of digital elevation model (DEM) terrains via multiscale analysis is proposed. The algorithm employs the lifting scheme to generate multiscale DEMs. At each scale, the areas of pixels that are modified are computed. Granulometric analysis is employed to compute the average area of curvature regions in the terrain, and the average roughness of the terrain due the distribution of curvature regions. The selected case studies of the algorithm implementation demonstrated that the proposed algorithm provides a surface roughness parameter that is realistic with respect to the amplitudes and frequencies of the terrain, invariant with respect to rotation and translation, and has intuitive meaning. The algorithm allows for a good quantification of a region's convexity/concavity over varying scales, distinguishing between shallow and deep incisions of valleys and ridges of the terrain, and hence, provides an accurate surface roughness parameter. © 2010 Elsevier Ltd.


Yusoff N.H.N.,Malaysian Science and Technology Research Institute for Defence | Ghazali M.J.,National University of Malaysia | Isa M.C.,Malaysian Science and Technology Research Institute for Defence | Daud A.R.,National University of Malaysia | And 2 more authors.
Materials and Design | Year: 2012

This paper discusses the effect of plasma spray parameters of deposited agglomerated nano Al2O3-13%TiO2 powders on commercial marine-grade mild steels. Prior to the coating work, the nanopowders were subjected to a two-level factorial design of experiment to optimize the operational spray parameters, namely, the primary gas pressure, the carrier gas pressure, and the powder feed rate. These operational spray parameters potentially affect the following responses of the coatings: microhardness, wear rate, and surface roughness. The significant effect on surface roughness is due to the interaction factor with the carrier gas pressure. However, by changing the carrier gas pressure and the powder feed rate, an insignificant effect on the microhardness and wear rate is noted. In general, agglomerated Al2O3-13%TiO2 nanopowder-coated steels, with the lowest primary pressure of 40psi, carrier gas pressure of 20psi, and the highest powder feed rate of 3rpm, are most preferred. © 2012 Elsevier Ltd.


Sathyamoorthy D.,Malaysian Science and Technology Research Institute for Defence
IOP Conference Series: Earth and Environmental Science | Year: 2014

The derivation of spatial significance is an important aspect of geospatial analysis and hence, various methods have been proposed to compute the spatial significance of entities based on spatial distances with other entities within the cluster. This paper is aimed at studying the spatial significance of mountain objects extracted from multiscale digital elevation models (DEMs). At each scale, the value of spatial significance index SSI of a mountain object is the minimum number of morphological dilation iterations required to occupy all the other mountain objects in the terrain. The mountain object with the lowest value of SSI is the spatially most significant mountain object, indicating that it has the shortest distance to the other mountain objects. It is observed that as the area of the mountain objects reduce with increasing scale, the distances between the mountain objects increase, resulting in increasing values of SSI. The results obtained indicate that the strategic location of a mountain object at the centre of the terrain is more important than its size in determining its reach to other mountain objects and thus, its spatial significance. © Published under licence by IOP Publishing Ltd.


Md Salleh R.,Malaysian Science and Technology Research Institute for Defence
Defence S and T Technical Bulletin | Year: 2014

The purpose of this paper is to identify the standard practices of researchers in Science and Technology Research Institute for Defence (STRIDE) in finding relevant online information to support their research. The study was conducted using the qualitative research approach to study the search behaviour used to retrieve relevant online information for their research projects and publications specifically in defence areas. Several interviews were conducted and the common practices carried out by researchers were identified. It was found that the researchers have their own preferences in conducting online searches. The study focused on four main themes as guidelines in collecting the data, which are search options, use of keywords, level of information relevancy and satisfaction. The findings indicated that most of the researchers use common search engines, in particular Google. Others prefer using websites with specific fields that meet their research requirements. Keyword search, using either single or multiple terms, is the most common technique used. Most of the searches conducted gave about 70% information relevancy. Despite the high relevancy of documents retrieved, the online search practices result in only 40% researchers' satisfaction.


Sathyamoorth D.,Malaysian Science and Technology Research Institute for Defence
Defence S and T Technical Bulletin | Year: 2014

The derivation of spatial significance is an important aspect of geospatial analysis and hence, various methods have been proposed to compute the spatial significance of entities based on spatial distances with other entities within the cluster. This paper is aimed at studying the spatial significance of mountain objects extracted from multiscale digital elevation models (DEMs). At each scale, the value of spatial significance index SSI of a mountain object is the minimum number of morphological dilation iterations required to occupy all the other mountain objects in the terrain. The mountain object with the lowest value of SSI is the spatially most significant mountain object, indicating that it has the shortest distance to the other mountain objects. It is observed that as the area of the mountain objects reduce with increasing scale, the distances between the mountain objects increase, resulting in increasing values of SSI. The results obtained indicate that the strategic location of a mountain object at the centre of the terrain is more important than its size in determining its reach to other mountain objects and thus, its spatial significance.


Sathyamoorthy D.,Malaysian Science and Technology Research Institute for Defence
Defence S and T Technical Bulletin | Year: 2010

This paper is aimed at conducting a critical assessment of two key defence R&D fi elds that are important in supporting the development of the national defence industry, in particular in supporting the achievement of the objectives of the Fourth Dimension Malaysian Armed Forces (4D MAF) capability plan in terms of operational awareness and mission capability. The fi elds that will be discussed, determined based on the author's literature review and opinions of the MAF's capabilities and requirements, and current and expected future trends of global defence technology development, are Command, Control, Communications, Computers, Intelligence, Surveillance & Reconnaissance (C4ISR) in support of network centric operations (NCO) and unmanned vehicles (UVs).On the whole, the overall capabilities of the national defence industry to produce indigenous equipment and assets that meet the requirements of the 4D MAF plan in these two fi elds of defence R&D are still relatively limited. Nevertheless, signifi cant progress has been, and is being, made through collaborations with relevant agencies, institutes and industries, both local and foreign. Active participation in defence R&D, in these two fi elds, in addition to other fi elds of defence technology, including vehicle & aerospace engineering challenges, emergent naval technology, smart weapons, personnel protection & performance, and biological, nuclear & chemical terrorism countermeasures, is required to further catalyze the development of the national defence industry.


Sathyamoorthy D.,Malaysian Science and Technology Research Institute for Defence
Defence S and T Technical Bulletin | Year: 2013

Global Navigation Satellite Systems (GNSS) are being increasingly used for a variety of important applications, including public safety services (police, fire, rescue and ambulance), marine and aircraft navigation, vehicle theft monitoring, cargo tracking, and critical time synchronisation for utility, telecommunications, banking and computer industries. At present, there are two types of GNSS signals; military GNSS signals (L1 P(Y) and L2 P(Y) for the case of GPS, and L1 for GLONASS) and civilian GNSS signals (L1 coarse acquisition (C/A) for GPS, and standard precision (SP) for GLONASS). Usage of L1 P(Y) and L2 P(Y), and HP signals are limited to the US and Russian militaries respectively. Other users only have access to civilian GNSS signals. Usage of civilian GNSS signals is growing rapidly due the quality of service provided by GNSS, ease of use and low user cost. However, unlike military GNSS signals, civilian GNSS signals are unencrypted and unauthenticated, making them vulnerable to spoofing, which refers to forging and transmission of navigation messages in order to manipulate the navigation solutions of GNSS receivers. Spoofing of civilian GNSS signals is surprisingly simple to conduct by even relatively unsophisticated adversaries. Due to the increasing reliance of various industries on GNSS, the consequences of GNSS spoofing can be severe, in terms of safety, environmental and economic damage. Hence, GNSS vulnerability mitigations steps should be given emphasis, including positioning/ navigation / timing (PNT) backups, making full use of on-going GNSS modernisation programmes, inference detection & monitoring (IDM), and counter-spoofing technologies. This paper is aimed at reviewing the vulnerability of civilian GNSS signals to spoofing and the steps that can be taken to mitigate this vulnerability.

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