Mahdi Modiri
Volume 5, Issue 17 , May 1996, Pages 2-5
Abstract
GIS, like other information systems, consists of sub systems. • Data entry sub-system; • storage and data-recovery Subsystem; • processing and data analysis Subsystem; • Information outlet Subsystem.
A system can be called a GIS whose software system includes all four of the above ...
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GIS, like other information systems, consists of sub systems. • Data entry sub-system; • storage and data-recovery Subsystem; • processing and data analysis Subsystem; • Information outlet Subsystem.
A system can be called a GIS whose software system includes all four of the above functions. Consequently, most digital mapping systems, remote sensing systems, and thematic mapping systems are not GIS.
Today, database management and analysis are important functions, but in the future, modern functionalities such as the use of artificial intelligence or visualization might come about, which will be among the most prominent features of GIS, and there is no reason why GIS should be limited only to the technology.
Abbasali Salehabadi (Translator)
Volume 5, Issue 17 , May 1996, Pages 6-10
Abstract
Automatic or semi-automatic short-range digital photogrammetric systems are among the most accurate and efficient instruments for most measurements in industrial production. This paper examines and illustrates the experiences and results of strategic studies on a short-range digital photogrammetric project ...
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Automatic or semi-automatic short-range digital photogrammetric systems are among the most accurate and efficient instruments for most measurements in industrial production. This paper examines and illustrates the experiences and results of strategic studies on a short-range digital photogrammetric project concerning the process of production. These results are related to the application of this technique in the production and quality control carried out in a North American shipyard.
The present article is the result of one of the five strategic research studies conducted by the ETH Institute of Geodesy and Photogrammetry of Zurich, at a shipyard workshop called (BIW) in Mainc, USA.
The purpose of these studies is, in fact, an accurate assessment of the implementation of modern digital photogrammetric systems in the measurement of events occurring during the production stages and their quality control in a shipyard workshop.
The project presented here is the dimensional control of various parts of the body of a ship before it is installed and finalized. In the BIW workshop, the various parts of a body with a nominal dimension of 12 x 25 x 25 meters and weighing several hundred tons are placed on each other and then they are individually prepared and then assembled, and eventually set in a part of the full body of the ship, which is placed in the shipyard.
This method of installing and fitting parts in the construction of ships usually results in an increase in financial costs due to freedom of action.
Mahdi Modiri
Volume 5, Issue 17 , May 1996, Pages 11-16
Abstract
Remote sensing is a science that provides valuable information on objects and land features by measuring distances from afar and without physical contact. In remote sensing, information can be obtained by measuring and recording the reflections of electromagnetic waves of atmosphere and ground level, ...
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Remote sensing is a science that provides valuable information on objects and land features by measuring distances from afar and without physical contact. In remote sensing, information can be obtained by measuring and recording the reflections of electromagnetic waves of atmosphere and ground level, which are received by sensors installed on satellites, and after their analysis, the necessary information is extracted. There are three major factors of reflection, absorption and passage in the collision of electromagnetic waves with any phenomenon, each of which depends on the wavelength of radiated energy and physical and chemical properties of the phenomenon, and the energy reflection from any phenomenon on the Earth is a function of wavelength, molecular and intracellular properties of the phenomenon and other physical characteristics of the objects under measurement. The satellite data originally contains various geometric and radiometric errors that are affected by satellite, sensor and atmospheric conditions, as well as errors in recording, transmission of information and other related issues. Satellite data become valuable and useful after making geometric and radiometric corrections. By performing geometric corrections, satellite information is readily to for analysis and utilization.
Abbasali Salehabadi (Translator)
Volume 5, Issue 17 , May 1996, Pages 17-22
Abstract
Russia's satellite navigation system, known as Glonass, will be completed in late 1995. This system consists of 24 satellites, which move in three elliptical orbits, at a distance of 19,100 kilometers from the Earth’s surface. These satellites introduce the Glonass system, which is subject to comparisons ...
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Russia's satellite navigation system, known as Glonass, will be completed in late 1995. This system consists of 24 satellites, which move in three elliptical orbits, at a distance of 19,100 kilometers from the Earth’s surface. These satellites introduce the Glonass system, which is subject to comparisons with its American counterpart. The question here is that what advantages there are in using either of these systems with a receiver. Currently, both of the navigation systems that are in operation are being investigated. The American system called GPS and Glonass each include 24 satellites. Although there are many similarities between the two systems, their characteristics are completely different, so that they are not effective in running the system.
Hasan Beikmohammadi
Volume 5, Issue 17 , May 1996, Pages 23-26
Abstract
Until thirty years ago, tourism and international travel were considered to be a luxury and fantasy even for quite wealthy people, while today the tourism industry has become one of the world's largest industries.
The number of international tourists which had not exceeded 25 million in 1950 has risen ...
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Until thirty years ago, tourism and international travel were considered to be a luxury and fantasy even for quite wealthy people, while today the tourism industry has become one of the world's largest industries.
The number of international tourists which had not exceeded 25 million in 1950 has risen to more than 500 million in 1993. During this period, revenues from this industry grew from $ 2.1 billion to $ 304 billion. According to the World Tourism Organization, the share of the Middle East, Southwest Asia and North Africa in this revenue has been only 4 percent, while Spain's income alone exceeds the oil revenue of all the Persian Gulf neighboring states, the Indonesian share is worth $ 3.3 billion, and France's share of the industry is nearly $ 100 billion. Undoubtedly, due to the diversity of weather, ancient history, several ancient and pilgrimage monuments, exquisite scenery, beautiful geographic landscapes and artworks, our country has a special potential in tourism industry which, if given due attention, it can soon become one of the world's largest tourist poles. But it should be noted that one of the realities of the tourism industry in each country is that this industry is not essentially either fortunate or despised, although there is no doubt that the development of this industry is very constructive in terms of foreign exchange earnings and added value, creation of employment, revitalizing weak local economies and cultural exchanges, but it is extremely undesirable if this industry is effective in destroying natural environments and in particular damaging culturally valuable spaces. Therefore, while, culturally, developing this industry leads to solidarity between nations and ultimately to international peace and understanding, and it also has countless economic advantages, but its growth and development is viewed in some international circles with concern and skepticism because of some negative effects. This article attempts to analyze the tourism industry in Iran and the province of Sistan and Baluchestan.
Abbas Khosravi
Volume 5, Issue 17 , May 1996, Pages 27-41
Abstract
The study area is located in central Iran and in the southern margin of a large depression along the northwest-southeast direction. This region is a desert part of which is formed by salt pan (Kavir). This region, like most of Iran's central areas, has been swept by sand for many years. The issue of ...
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The study area is located in central Iran and in the southern margin of a large depression along the northwest-southeast direction. This region is a desert part of which is formed by salt pan (Kavir). This region, like most of Iran's central areas, has been swept by sand for many years. The issue of sand is most threatening toward villages in the north and northeast of Kashan, namely Aran and Bidgol, and four villages of Abu Zaidabad, including Mohammad Abad, Gaz, Fakhra, Qasim Abad, Yazd Delan and Hossein Abad. It covers houses, roads, water wells and fields, and increases aridity in the area. Kashan region is a small part of a natural, morphologic and geologic unit, divided into two distinct parts:
A) Raised areas known as the southern part of Kashan mountain range, or Karkass mountain range,
(B) Depression of Qom-Kashan-Ardakan Qom-Kashan-Ardakan depression is in fact a wide plain valley that is limited to volcanic rocky mountains, and the faults lying all along the foot of this mountain range have caused it to rise. This depression, due to thick and folded deposits of Neogene red layers which are partly degraded, is filled in the sea section of Qom formations which is of the Oligo-Miocene age, and is covered by Bahada deposits, sand, large rubbles, playa sediments and finally sandy hills.
Alireza Owsati (Translator)
Volume 5, Issue 17 , May 1996, Pages 42-61
Abstract
Water resources forms part of hydrology that is linked to hydrological characteristics that are clearly variable in time and space. The information contained in the archive basically provides cheaper information sources and this issue should be considered before new measures are initiated. For small-scale ...
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Water resources forms part of hydrology that is linked to hydrological characteristics that are clearly variable in time and space. The information contained in the archive basically provides cheaper information sources and this issue should be considered before new measures are initiated. For small-scale studies, measurements with ground-based equipment provide a very good solution for engineering issues. Ground-based devices are able to acquire highly precise data over a range of time frequencies and are able to operate under any atmospheric conditions. Their major fault is that they perform the measurement only for one point that represents the whole. In order to compensate for this defect, the number of ground-based measurements for the point, which is determined by the time needed to install the equipment, manpower for installation, process and analysis of the data, and most importantly the cost of purchase and operation, can be increased.
Remote sensing methods are able to measure surface level variability, which can never be measured from the ground surface, and include the alignment of ground-based measurements precision. Ground-based measurement control, such as a spectral reflector, should often accompany remote sensing data acquisition. Refer to Figure 1.
Integrating a limited number of ground-based measurements can prevent great waste of the staff’s time in the desert. In this part, remote sensing performance is discussed in terms of behavioral evaluation of the hydrological changes that are of importance for civil engineers.
Fatemeh Razi'ee (Translator)
Volume 5, Issue 17 , May 1996, Pages 62-64
Abstract
Stars have incredibly long life spans by human standards, but they are not eternal. The sun is a middle-aged star (in the middle part of its lifetime). Previous generations of stars have lived and died, and new stars are still born in our galaxy. The stars are formed by the collapse of gas clouds due ...
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Stars have incredibly long life spans by human standards, but they are not eternal. The sun is a middle-aged star (in the middle part of its lifetime). Previous generations of stars have lived and died, and new stars are still born in our galaxy. The stars are formed by the collapse of gas clouds due to gravity. The cloud will only collapse if its density is sufficient, and it should be sufficiently cool and bulky so that the gravity can overcome its internal pressure. For this reason, the most favorable condition for the formation of stars is molecular cloud. Dense-shaped gas clouds have very high number of molecules and are covered with dust that keeps them cool. If part of this cloud or the whole of it finds internal interactions due to gravity, it is likely that it decompose into smaller entities, each of which becomes a star. Hence the formation of stars takes place in batches. The Parvin (Pleiades) star cluster, for example, consists of a group of stars that have been formed around 50 million years ago.
